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+%D The calculator
+%D
+%D This document was made in 1998 as demonstration of widgets in \CONTEXT in \MKII.
+%D It has been adapted to run in \MKIV. Not many changes were needed. The macro
+%D definitions are layout a bit more readable and we use official scratch variables.
+%D
+%D The \JAVASCRIPT\ interpeter has changes and also became more strict. So, I
+%D reformatted the code bit and added some more semicolons and vars.
+%D
+%D We changed to font from a Helvetica lookalike to Dejavu but kept the colors as
+%D in the original. We also kept the \JAVASCRIPT\ and \METAPOST\ code (although
+%D we had to add some initalizations for \METAPOST\ due to the runtime graphic
+%D generation. I didn't check the functionality.
+%D
+%D Should I do it different nowaways? For sure. I might use layers of make nicer
+%D \METAPOST\ code but it's also a demonstration of how thinsg were done in 1998.
+
+% acrobat 3->4 : different field initialization
+% acrobat 4->5 : typecasting fails [switch"2" vs 2]
+% acrobat 6-> : more strict interpreter
+
+\starttext
+
+\dontcomplain
+
+\setuppapersize
+ [S6][S6]
+
+\setupwhitespace
+ [medium]
+
+\setupbodyfont
+ [dejavu,9pt]
+
+\setuptyping
+ [margin=standard]
+
+\setuplayout
+ [backspace=1cm,
+ topspace=1cm,
+ header=0pt,
+ footer=0pt,
+ width=middle,
+ height=middle]
+
+\setupinteraction
+ [page=yes,
+ state=start,
+ author=Hans Hagen,
+ title=The Calculator,
+ color=keyboard]
+
+\setupinteractionscreen
+ [option=max]
+
+\definecolor [action] [r= 1, g=.9, b=.5]
+\definecolor [keyboard] [r= 0, g=.7, b=.7]
+\definecolor [stack] [r=.7, g=.6, b=.8]
+
+\useURL[pragma-mail][mailto:pragma@xs4all.nl][][pragma@xs4all.nl]
+
+%D We have to use \type {String(...)=""} otherwise zero is regarded
+%D as non|-|entry (empty). This is a bit fuzzy.
+
+\def\MinLevel{50}
+\def\MaxLevel {8}
+
+\startJSpreamble {variables} used now
+
+ var Growing = false ;
+ var MinLevel = -50 ;
+ var MaxLevel = 8 ;
+ var Level = 1 ;
+ var NoErrorFound = ">ok" ;
+ var NoValueError = ">invalid" ;
+ var WhateverError = ">error" ;
+ var OverflowError = ">overflow" ;
+ var ExhaustedError = ">exhausted" ;
+
+ var Stack = new Array() ;
+ var Stats = new Array() ;
+
+ // console.clear() ;
+
+ // console.println("preamble loaded: variables") ;
+
+\stopJSpreamble
+
+\startJSpreamble {housekeeping} used now
+
+ function do_reset_all () {
+ if (Growing) {
+ Level = 1 ;
+ } else {
+ Level = MaxLevel ;
+ }
+ for (var i=MinLevel ; i<=MaxLevel ; i++) {
+ Stack[i] = "" ;
+ }
+ do_mark (NoErrorFound) ;
+ }
+
+ function do_refresh (i) {
+ var vv = this.getField("Stack." + String(i)) ;
+ if (vv) {
+ vv.value = Stack[i] ;
+ vv.readonly = (i != Level) ;
+ this.dirty = false ;
+ }
+ }
+
+ function do_refresh_all () {
+ for (var i=1 ; i<=MaxLevel ; i++) {
+ do_refresh(i) ;
+ }
+ }
+
+ function do_update_A () {
+ if (Stack[1] == "") {
+ for (var i=1 ; i<=MaxLevel ; i++) {
+ vv = this.getField("Stack." + String(i)) ;
+ if (vv) {
+ Level = i ;
+ if (valid_number(vv.value)) {
+ Stack[Level] = String(vv.value)
+ } else {
+ vv.value = "" ;
+ this.dirty = false ;
+ return ;
+ }
+ }
+ }
+ }
+ }
+
+ function do_update_B () {
+ if (String(Stack[MaxLevel-1]) == "") {
+ for (var i=1 ; i<=MaxLevel ; i++) {
+ vv = this.getField("Stack." + String(i)) ;
+ if (vv) {
+ if (valid_number(vv.value)) {
+ Stack[Level] = String(vv.value) ;
+ } else {
+ vv.value = "" ;
+ this.dirty = false ;
+ return ;
+ }
+ }
+ }
+ }
+ }
+
+ function do_update () {
+ if (Growing) {
+ do_update_A() ;
+ } else {
+ do_update_B() ;
+ }
+ }
+
+ function do_mark (s) {
+ var vv = this.getField("Stack." + String(Level)) ;
+ if (vv) {
+ vv.value = s ;
+ this.dirty = false ;
+ }
+ }
+
+ // console.println("preamble loaded: housekeeping") ;
+\stopJSpreamble
+
+\startJSpreamble {handling} used now
+
+ function do_enter () {
+ do_update() ;
+ var vv = this.getField("Stack." + String(Level)) ;
+ if ((vv.value!=Stack[Level]) && (String(vv.value).search(/>/)==-1)) {
+ do_push (vv.value) ;
+ } else {
+ do_push (Stack[Level]) ;
+ }
+ }
+
+ function do_push_A (Value) {
+ do_update() ;
+ Stack[Level] = String(Value) ;
+ do_parse(Level) ;
+ if (String(Stack[Level])!="") {
+ if (Level<MaxLevel) {
+ ++Level ;
+ do_mark (ErrorString) ;
+ } else {
+ for (var i=MinLevel ; i<MaxLevel ; i++) {
+ Stack[i] = Stack[i+1] ;
+ }
+ Stack[MaxLevel] = "" ;
+ do_refresh_all() ;
+ if (String(Stack[MinLevel])!="") {
+ ErrorString = ExhaustedError ;
+ }
+ do_mark (ErrorString) ;
+ }
+ }
+ }
+
+ function do_push_B (Value) {
+ do_update() ;
+ Stack[MaxLevel] = String(Value) ;
+ do_parse(MaxLevel) ;
+ if (String(Stack[MaxLevel])!="") {
+ for (var i=MinLevel ; i<MaxLevel ; i++) {
+ Stack[i] = Stack[i+1] ;
+ }
+ Stack[MaxLevel] = "" ;
+ do_refresh_all() ;
+ if (Stack[MinLevel]!="") {
+ ErrorString = ExhaustedError ;
+ }
+ do_mark (ErrorString) ;
+ }
+ }
+
+ function do_push (Value) {
+ if (Growing) {
+ do_push_A (Value) ;
+ } else {
+ do_push_B (Value) ;
+ }
+ }
+
+ function do_pop_A () {
+ do_update() ;
+ if (String(Stack[0])!="") {
+ for (var i=MaxLevel ; i>MinLevel ; i--) {
+ Stack[i] = Stack[i-1] ;
+ }
+ Stack[MinLevel] = "" ;
+ do_refresh_all() ;
+ Level = MaxLevel ;
+ } else {
+ while ((Level>1) && (String(Stack[Level])=="")) {
+ do_refresh(Level) ;
+ --Level ;
+ }
+ }
+ if (String(Stack[Level])=="") {
+ return("") ;
+ } else {
+ Value = Number(Stack[Level]) ;
+ Stack[Level] = "" ;
+ do_refresh(Level) ;
+ return(Value) ;
+ }
+ }
+
+ function do_pop_B () {
+ do_update() ;
+ if (String(Stack[MaxLevel])=="") {
+ for (var i=MaxLevel ; i>MinLevel ; i--) {
+ Stack[i] = Stack[i-1] ;
+ }
+ Stack[MinLevel] = "" ;
+ do_refresh_all() ;
+ }
+ if (String(Stack[MaxLevel])=="") {
+ return("") ;
+ } else {
+ Value = Number(Stack[MaxLevel]) ;
+ Stack[MaxLevel] = "" ;
+ return(Value) ;
+ }
+ }
+
+ function do_pop () {
+ if (Growing) {
+ return(do_pop_A()) ;
+ } else {
+ return(do_pop_B()) ;
+ }
+ }
+
+ function do_dup () {
+ var X = do_pop() ;
+ if (valid_number(X)) {
+ do_push(X) ;
+ do_push(X) ;
+ } else {
+ do_mark (ErrorString) ;
+ }
+ }
+
+ function do_parse ( i ) {
+ if (valid_number(Stack[i])) {
+ Stack[i] = parseFloat(Stack[i]) ;
+ do_refresh(i) ;
+ } else {
+ Stack[i] = "" ;
+ do_refresh(i) ;
+ do_mark (ErrorString) ;
+ }
+ }
+
+ function do_digit ( d ) {
+ Stack[Level] += String(d) ;
+ do_refresh(Level) ;
+ }
+
+ function valid_number ( x ) {
+ if (String(x) == "") {
+ ErrorString = NoValueError ;
+ return(false) ;
+ } else if (isNaN(x)) {
+ ErrorString = NoValueError ;
+ return(false) ;
+ } else if (isFinite(x)) {
+ ErrorString = NoErrorFound ;
+ return(true) ;
+ } else {
+ ErrorString = OverflowError ;
+ return(false) ;
+ }
+ }
+
+ // console.println("preamble loaded: handling") ;
+
+\stopJSpreamble
+
+\startJSpreamble {operations} used now
+
+ function do_calculate (Operator) {
+ do_enter() ;
+ var Y = do_pop() ;
+ var X = 0 ;
+ if (valid_number(Y)) {
+ X = do_pop() ;
+ if (valid_number(X)) {
+ switch (Number(Operator)) {
+ case 1 :
+ if (Y) {
+ X /= Y ;
+ }
+ break ;
+ case 2 :
+ X *= Y ;
+ break ;
+ case 3 :
+ X -= Y ;
+ break ;
+ case 4 :
+ X += Y ;
+ break ;
+ case 5 :
+ X = Math.max(X,Y) ;
+ break ;
+ case 6 :
+ X = Math.min(X,Y) ;
+ break ;
+ case 7 :
+ X = Math.pow(X,Y) ;
+ break
+ }
+ do_push(X) ;
+ } else {
+ do_push(Y) ;
+ ErrorString = NoValueError ;
+ }
+ }
+ do_mark(ErrorString) ;
+ }
+
+ // console.println("preamble loaded: operations") ;
+\stopJSpreamble
+
+\startJSpreamble {functions} used now
+
+ function do_facultate (Value) {
+ var n = Math.min(Math.round(Value),500) ;
+ if (n <= 1) {
+ return(1) ;
+ } else {
+ var m = 1 ;
+ for (m=1, i=1 ; i<=n ; i++) {
+ m = m * i ;
+ }
+ return(m) ;
+ }
+ }
+
+ function do_constant (Operation) {
+ do_update() ;
+ switch (Number(Operation)) {
+ case 1 :
+ do_push(Math.PI) ;
+ break ;
+ case 2 :
+ do_push(Math.E) ;
+ break ;
+ case 3 :
+ do_push(Math.random(1)) ;
+ break ;
+ case 4 :
+ do_dup() ;
+ break ;
+ }
+ }
+
+ function do_do_memory (mv, Sign) {
+ var X = do_pop() ;
+ if (valid_number(X)) {
+ mv.value += Sign*X ;
+ if (!valid_number(mv.value)) {
+ mv.value = "" ;
+ }
+ this.dirty = false ;
+ }
+ do_mark(ErrorString) ;
+ }
+
+ function do_memory (Operation) {
+ var mv = this.getField("Stats.mem") ;
+ if (mv) {
+ switch (Number(Operation)) {
+ case 1 :
+ mv.value = "" ;
+ break ;
+ case 2 :
+ do_do_memory(mv, 1) ;
+ break ;
+ case 3 :
+ do_do_memory(mv, -1) ;
+ break ;
+ case 4 :
+ if (mv.value == "") {
+ ErrorString = NoValueError ;
+ do_mark(ErrorString) ;
+ } else {
+ do_push(mv.value) ;
+ }
+ break ;
+ }
+ this.dirty = false ;
+ }
+ }
+
+ function do_operation (Operator) {
+ do_enter() ;
+ var X = do_pop() ;
+ if (valid_number(X)) {
+ switch (Number(Operator)) {
+ case 1 :
+ do_push(Math.sin(X)) ;
+ break ;
+ case 2 :
+ do_push(Math.cos(X)) ;
+ break ;
+ case 3 :
+ do_push(Math.tan(X)) ;
+ break ;
+ case 4 :
+ do_push(Math.exp(X)) ;
+ break ;
+ case 5 :
+ do_push(Math.ceil(X)) ;
+ break ;
+ case 6 :
+ do_push(Math.pow(X,2)) ;
+ break ;
+ case 7 :
+ do_push(do_facultate(X)) ;
+ break ;
+ case 8 :
+ do_push(Math.asin(X)) ;
+ break ;
+ case 9 :
+ do_push(Math.acos(X)) ;
+ break ;
+ case 10 :
+ do_push(Math.atan(X)) ;
+ break ;
+ case 11 :
+ do_push(Math.log(X)) ;
+ break ;
+ case 12 :
+ do_push(Math.floor(X)) ;
+ break ;
+ case 13 :
+ do_push(Math.sqrt(X)) ;
+ break ;
+ case 14 :
+ do_push(Math.round(X)) ;
+ break ;
+ case 15 :
+ do_push(Math.pow(X,-1)) ;
+ break ;
+ case 16 :
+ do_push(X*(2*Math.PI/360)) ;
+ break ;
+ case 17 :
+ do_push(X/(2*Math.PI/360)) ;
+ break ;
+ case 18 :
+ do_push(-X) ;
+ break ;
+ }
+ }
+ do_mark(ErrorString) ;
+ }
+
+ // console.println("preamble loaded: functions") ;
+\stopJSpreamble
+
+\startJSpreamble {statistics} used now
+
+ var s_min_max = 1 ;
+ var s_sqrt = 0 ;
+
+ function do_statcalcs (Sign, X) {
+ s_n.value += Sign ;
+ s_sqrt += Sign*X*X ;
+ s_total.value += Sign*X ;
+ s_mean.value = s_total.value / s_n.value ;
+ s_temp = Math.max(s_sqrt - 2*s_total.value*s_mean.value +
+ s_n.value*s_mean.value*s_mean.value, 0) ;
+ s_sdev.value = Math.sqrt(s_temp/s_n.value) ;
+ if (!(valid_number(X) && valid_number(s_sqrt) &&
+ valid_number(s_sdev.value) && valid_number(s_total.value) &&
+ valid_number(s_mean.value))) {
+ do_statistics(1) ;
+ }
+ this.dirty = false ;
+ }
+
+ function do_statistics(Operator) {
+ var s_n = this.getField("Stats.n") ;
+ var s_min = this.getField("Stats.min") ;
+ var s_max = this.getField("Stats.max") ;
+ var s_total = this.getField("Stats.total") ;
+ var s_mean = this.getField("Stats.mean") ;
+ var s_sdev = this.getField("Stats.sdev") ;
+ if ((s_sqrt==0) && (s_n.value!="") && (s_n.value>0)) {
+ s_min_max = 1 ;
+ s_sqrt = s_n.value*s_sdev.value*s_sdev.value +
+ 2*s_total.value*s_mean.value -
+ s_n.value*s_mean.value*s_mean.value ;
+ }
+ switch (Number(Operator)) {
+ case 1 :
+ s_min_max = 1 ;
+ s_n.value = "" ;
+ s_min.value = "" ;
+ s_max.value = "" ;
+ s_total.value = "" ;
+ s_mean.value = "" ;
+ s_sdev.value = "" ;
+ s_sqrt = 0 ;
+ break ;
+ case 2 :
+ do_enter() ;
+ var X = do_pop() ;
+ if (valid_number(X)) {
+ if (s_n.value=="") {
+ s_n.value = 0 ;
+ s_total.value = 0 ;
+ s_mean.value = 0 ;
+ if (s_min_max) {
+ s_min.value = X ;
+ s_max.value = X ;
+ }
+ } else {
+ if ((s_min_max) && (X<s_min.value)) {
+ s_min.value = X ;
+ }
+ if ((s_min_max) && (X>s_max.value)) {
+ s_max.value = X ;
+ }
+ }
+ do_statcalcs(1,X) ;
+ }
+ break ;
+ case 3 :
+ do_enter() ;
+ var X = do_pop() ;
+ if (valid_number(X)) {
+ s_min.value = "" ;
+ s_max.value = "" ;
+ s_min_max = 0 ;
+ if (s_n.value>0) {
+ do_statcalcs(-1,X) ;
+ } else {
+ do_statistics(1) ;
+ }
+ }
+ break ;
+ }
+ do_mark(ErrorString) ;
+ this.dirty = false ;
+ }
+
+ function do_copystat (Field) {
+ var sv = this.getField("Stats.".concat(Field)) ;
+ do_push(sv.value) ;
+ }
+
+ // console.println("preamble loaded: statistics") ;
+\stopJSpreamble
+
+\startJSpreamble {initialization} used now
+ do_reset_all() ;
+ do_update() ;
+ do_refresh_all() ;
+ do_mark (NoErrorFound) ;
+
+ // console.println("preamble loaded: initialization") ;
+\stopJSpreamble
+
+%D We could use functions instead but this demonstrates inline
+%D code. We also could use predefined references.
+
+\startJScode{period}
+ if (Stack[Level].search(/[.|e]/)==-1) {
+ do_digit(".") ;
+ }
+\stopJScode
+
+\startJScode{sign}
+ L = Stack[Level].length ;
+ if ((L==0) || (Stack[Level].charAt(L-1)=="e")) {
+ do_digit("-") ;
+ }
+\stopJScode
+
+\startJScode{exponent}
+ L = Stack[Level].length ;
+ if ((L>0) && valid_number(Stack[Level]) && (Stack[Level].search(/[e]/)==-1)) {
+ do_digit("e") ;
+ }
+\stopJScode
+
+\startJScode{reset}
+ do_reset_all() ;
+ do_refresh_all() ;
+ do_mark (NoErrorFound) ;
+\stopJScode
+
+\startJScode{clear}
+ do_update() ;
+ Stack[Level] = String(Stack[Level]).substring(0,String(Stack[Level]).length-1) ;
+ do_refresh(Level) ;
+\stopJScode
+
+\startJScode{pop}
+ X = do_pop() ;
+ do_mark(NoErrorFound) ;
+\stopJScode
+
+\startJScode{push}
+ do_enter() ;
+\stopJScode
+
+\startJScode{grow}
+ Growing = !Growing ;
+ do_reset_all() ;
+ do_refresh_all() ;
+ do_mark (NoErrorFound) ;
+\stopJScode
+
+% graphics
+
+\startuniqueMPgraphic{page}
+ fill OverlayBox
+ withcolor .4white ;
+ draw OverlayBox enlarged -10pt
+ withpen pencircle scaled 5pt
+ withcolor .8white ;
+\stopuniqueMPgraphic
+
+\startuniqueMPgraphic{shape}
+ path p ; color c ;
+ p := OverlayBox ;
+ c := \overlaycolor ;
+ fill p withcolor c ;
+ draw p withpen pencircle scaled 1.5pt withcolor .8c ;
+\stopuniqueMPgraphic
+
+\defineoverlay [page] [\uniqueMPgraphic{page}]
+\defineoverlay [shape] [\uniqueMPgraphic{shape}]
+
+\setupbackgrounds
+ [page]
+ [background=page]
+
+\definemeasure[ButtonWidth][\makeupwidth/15]
+
+\setupbuttons
+ [width=\measured{ButtonWidth},
+ height=\measured{ButtonWidth},
+ background=shape,
+ backgroundcolor=\MPcolor{keyboard},
+ frame=off,
+ style=,
+ color=]
+
+\setupfield
+ [Results]
+ [horizontal,frame]
+ [width=fit,
+ align={lohi},
+ height=.5\measured{ButtonWidth},
+ background=shape,
+ backgroundcolor=\MPcolor{stack},
+ frame=off]
+ [width=3.5\measured{ButtonWidth},
+ frame=off]
+ [width=3.5\measured{ButtonWidth},
+ height=.45\measured{ButtonWidth},
+ option=readonly,
+ frame=off]
+
+\starttexdefinition unexpanded Star
+ \lower.65ex\hbox {
+ *
+ }
+\stoptexdefinition
+
+\starttexdefinition unexpanded InfoButton #1
+ \setbox\scratchbox\hbox {
+ \lower .5cm \hbox {
+ \button [
+ width=\dimexpr\overlaywidth + .5cm\relax,
+ height=\dimexpr\overlayheight + .5cm\relax,
+ strut=no,
+ frame=off,
+ background=
+ ] {
+ } [
+ info:#1
+ ]
+ }
+ }
+ \wd\scratchbox\overlaywidth
+ \ht\scratchbox\overlayheight
+ \box\scratchbox
+\stoptexdefinition
+
+\starttexdefinition unexpanded SomeKey #1#2#3
+
+ \bgroup
+
+ \doifelsenothing {#2} {
+ \button[background=]{#2}[#3]
+ } {
+ \defineoverlay
+ [infobutton]
+ [\InfoButton{#1}]
+ % \button
+ % [background={infobutton,shape}]
+ % {#2}
+ % [#3]
+ \framed
+ [offset=overlay,
+ frame=off,
+ background=infobutton,
+ backgroundcolor=red]
+ {\button{#2}[#3]}
+ }
+
+ \egroup
+
+ \ignorespaces
+
+\stoptexdefinition
+
+\starttexdefinition unexpanded StatField #1
+ \hbox \bgroup
+ \doifelsenothing {#1} {
+ \framed [
+ height=.5\measured{ButtonWidth},
+ width=3.5\measured{ButtonWidth},
+ frame=off
+ ] {
+ }
+ } {
+ \definefield[Stats.#1][line][Results]
+ \field[Stats.#1][option=readonly]
+ }
+ \egroup
+ \ignorespaces
+\stoptexdefinition
+
+\setbox\scratchboxone=\hbox to .4\makeupwidth \bgroup
+ \ss
+ \SomeKey {7} {\ssb 7} {JS(do_digit{7})} \hss
+ \SomeKey {8} {\ssb 8} {JS(do_digit{8})} \hss
+ \SomeKey {9} {\ssb 9} {JS(do_digit{9})} \hss
+ \SomeKey {div} {\ssb /} {JS(do_calculate{1})} \hss
+ \SomeKey {del} {del} {JS(clear)}
+\egroup
+
+\setbox\scratchboxtwo=\hbox to \wd\scratchboxone \bgroup
+ \ss
+ \SomeKey {4} {\ssb 4} {JS(do_digit{4})} \hss
+ \SomeKey {5} {\ssb 5} {JS(do_digit{5})} \hss
+ \SomeKey {6} {\ssb 6} {JS(do_digit{6})} \hss
+ \SomeKey {mul} {\ssb \Star} {JS(do_calculate{2})} \hss
+ \SomeKey {E} {E} {JS(exponent)}
+\egroup
+
+\setbox\scratchboxthree=\hbox to \wd\scratchboxone \bgroup
+ \ss
+ \SomeKey {1} {\ssb 1} {JS(do_digit{1})} \hss
+ \SomeKey {2} {\ssb 2} {JS(do_digit{2})} \hss
+ \SomeKey {3} {\ssb 3} {JS(do_digit{3})} \hss
+ \SomeKey {sub} {\ssb --} {JS(do_calculate{3})} \hss
+ \SomeKey {pop} {pop} {JS(pop)}
+\egroup
+
+\setbox\scratchboxfour=\hbox to \wd\scratchboxone \bgroup
+ \ss
+ \SomeKey {0} {\ssb 0} {JS(do_digit{0})} \hss
+ \SomeKey {period} {\ssb .} {JS(period)} \hss
+ \SomeKey {sign} {\ssb -} {JS(sign)} \hss
+ \SomeKey {add} {\ssb +} {JS(do_calculate{4})} \hss
+ \SomeKey {push} {push} {JS(push)}
+\egroup
+
+\setbox\scratchboxone=\vbox to .8\wd\scratchboxone \bgroup
+ \box\scratchboxone \vss
+ \box\scratchboxtwo \vss
+ \box\scratchboxthree\vss
+ \box\scratchboxfour
+\egroup
+
+\setbox\scratchboxtwo=\vbox to \ht\scratchboxone \bgroup
+ \dostepwiserecurse {\MaxLevel} {1} {-1} {
+ \definefield[Stack.\recurselevel][line][Results]
+ \hbox \bgroup
+ \field[Stack.\recurselevel][option=readonly]%
+ \egroup
+ \vfill
+ }
+ \unskip
+\egroup
+
+\setbox\scratchboxthree=\vbox to \ht\scratchboxone \bgroup
+ \StatField {n} \vfill
+ \StatField {min} \vfill
+ \StatField {max} \vfill
+ \StatField {total} \vfill
+ \StatField {mean} \vfill
+ \StatField {sdev} \vfill
+ \StatField {} \vfill
+ \StatField {}
+\egroup
+
+\setbox\scratchboxfour=\vbox to \ht\scratchboxone \bgroup
+ \ss\setstrut
+ \setupbuttons
+ [width=\measured{ButtonWidth},
+ height=.5\measured{ButtonWidth},
+ backgroundcolor=\MPcolor{action}]%
+ \SomeKey {sn} {n} {JS(do_copystat{n})} \vfill
+ \SomeKey {smin} {min} {JS(do_copystat{min})} \vfill
+ \SomeKey {smax} {max} {JS(do_copystat{max})} \vfill
+ \SomeKey {stotal} {total} {JS(do_copystat{total})} \vfill
+ \SomeKey {smean} {mean} {JS(do_copystat{mean})} \vfill
+ \SomeKey {ssdev} {sdev} {JS(do_copystat{sdev})} \vfill
+ \SomeKey {} {} {} \vfill
+ \SomeKey {} {} {}
+\egroup
+
+\setbox\scratchboxone=\hbox to \hsize \bgroup
+ \box\scratchboxone \hss
+ \box\scratchboxtwo \hss
+ \box\scratchboxthree\hss
+ \box\scratchboxfour
+\egroup
+
+\setupbuttons
+ [width=1.5cm,
+ height=1cm,
+ backgroundcolor=\MPcolor{action}]
+
+\setbox\scratchboxtwo=\hbox to \wd\scratchboxone \bgroup
+ \ss\setstrut
+ \SomeKey {sin} {sin} {JS(do_operation{1})} \hss
+ \SomeKey {cos} {cos} {JS(do_operation{2})} \hss
+ \SomeKey {tan} {tan} {JS(do_operation{3})} \hss
+ \SomeKey {max} {max} {JS(do_calculate{5})} \hss
+ \SomeKey {exp} {exp} {JS(do_operation{4})} \hss
+ \SomeKey {ceil} {ceil} {JS(do_operation{5})} \hss
+ \SomeKey {sqr} {x\high{2}} {JS(do_operation{6})} \hss
+ \SomeKey {fac} {x!} {JS(do_operation{7})} \hss
+ \SomeKey {pow} {x\high{y}} {JS(do_calculate{7})} \hss
+ \SomeKey {rad} {rad} {JS(do_operation{16})}
+\egroup
+
+\setbox\scratchboxthree=\hbox to \wd\scratchboxone \bgroup
+ \ss\setstrut
+ \SomeKey {asin} {asin} {JS(do_operation{8})} \hss
+ \SomeKey {acos} {acos} {JS(do_operation{9})} \hss
+ \SomeKey {atan} {atan} {JS(do_operation{10})} \hss
+ \SomeKey {min} {min} {JS(do_calculate{6})} \hss
+ \SomeKey {ln} {ln} {JS(do_operation{11})} \hss
+ \SomeKey {floor}{floor} {JS(do_operation{12})} \hss
+ \SomeKey {sqrt} {sqrt} {JS(do_operation{13})} \hss
+ \SomeKey {round}{round} {JS(do_operation{14})} \hss
+ \SomeKey {inv} {1/x} {JS(do_operation{15})} \hss
+ \SomeKey {deg} {deg} {JS(do_operation{17})}
+\egroup
+
+\setbox\scratchboxfour=\hbox to \wd\scratchboxone \bgroup
+ \ss\setstrut
+ \SomeKey {} {} {} \hss
+ \SomeKey {} {} {} \hss
+ \setupbuttons
+ [backgroundcolor=\MPcolor{keyboard}]%
+ \SomeKey {new} {new} {JS(reset)} \hss
+ \SomeKey {} {} {} \hss
+ \SomeKey {} {} {} \hss
+ \SomeKey {} {} {} \hss
+ \SomeKey {} {} {} \hss
+ \SomeKey {newn} {new} {JS(do_statistics{1})} \hss
+ \SomeKey {addn} {+n} {JS(do_statistics{2})} \hss
+ \SomeKey {subn} {--n} {JS(do_statistics{3})}
+\egroup
+
+\setbox\scratchboxfive=\hbox to \wd\scratchboxone \bgroup
+ \ss\setstrut
+ \SomeKey {neg} {--x} {JS(do_operation{18})} \hss
+ \SomeKey {random}{random} {JS(do_constant{3})} \hss
+ \SomeKey {pi} {pi} {JS(do_constant{1})} \hss
+ \SomeKey {e} {e} {JS(do_constant{2})} \hss
+ \SomeKey {dup} {dup} {JS(do_constant{4})} \hss
+ \SomeKey {} {} {} \hss
+ \SomeKey {} {} {} \hss
+ \setupbuttons
+ [backgroundcolor=\MPcolor{keyboard}]%
+ \SomeKey {} {} {} \hss
+ \SomeKey {exit} {exit} {CloseDocument} \hss
+ \SomeKey {help} {info} {info:help}
+\egroup
+
+\setbox\scratchboxsix=\hbox to \wd\scratchboxone \bgroup
+ \ss\setstrut
+ \setupbuttons
+ [width=\measured{ButtonWidth},
+ height=.5\measured{ButtonWidth},
+ backgroundcolor=\MPcolor{keyboard}]%
+ \SomeKey {newmem} {new} {JS(do_memory{1})} \hss
+ \SomeKey {addmem} {+m} {JS(do_memory{2})} \hss
+ \SomeKey {submem} {--m} {JS(do_memory{3})} \hss
+ \StatField {mem} \hss
+ \setupbuttons
+ [backgroundcolor=\MPcolor{action}]%
+ \SomeKey {copmem} {mem} {JS(do_memory{4})} \hss
+ \SomeKey {} {} {} \hss
+ \setupbuttons
+ [backgroundcolor=\MPcolor{stack}]%
+ \SomeKey {grow} {grow} {JS(grow)} \hss
+ \StatField {}
+\egroup
+
+\startstandardmakeup
+
+ \pagereference[calculator]
+
+ \vfill
+
+ \hbox to \hsize \bgroup
+ \hss
+ \vbox to \vsize \bgroup
+ \box\scratchboxtwo \vss
+ \box\scratchboxthree\vss
+ \box\scratchboxone \vss
+ \box\scratchboxfour \vss
+ \box\scratchboxfive \vss
+ \box\scratchboxsix
+ \egroup
+ \hss
+ \egroup
+
+ \vfill
+
+\stopstandardmakeup
+
+\starttexdefinition unexpanded BackgroundButton
+ \button [
+ background=screen,
+ backgroundscreen=.8,
+ backgroundoffset=5pt,
+ height=\vsize,
+ width=\hsize
+ ] {
+ } [
+ calculator
+ ]
+\stoptexdefinition
+
+\setuptexttexts
+ [\BackgroundButton]
+ []
+
+\starttexdefinition unexpanded Key #1#2
+ \goto {
+ \ss#1
+ } [
+ info:#2
+ ]
+\stoptexdefinition
+
+\startstandardmakeup[top=,bottom=]
+
+ \switchtobodyfont[8pt]
+
+ \start
+
+ \setupwhitespace[big]
+
+ \midaligned{\ssd The Calculator}
+
+ \blank[2*big]
+
+ \pagereference[info:help]
+ This calculator is stack based, which means that one enters values and
+ invokes an action that acts on the value(s) last entered. Subtracting 10 from
+ 20 using (\Key {--} {sub}) for instance comes down to clicking:
+
+ \startnarrower\ss
+ 10\quad in\quad 20\quad --
+ \stopnarrower
+
+ while calculating a sinus (\Key {sin} {sin}) results from entering:
+
+ \startnarrower\ss
+ .89\quad sin
+ \stopnarrower
+
+ The left column of fields (numbers) shows the Stack. One uses \Key {push}
+ {push} to push a value on the stack and \Key {pop} {pop} to remove a value.
+ Clicking \Key {new} {new} removes them all and the \Key {del} {del} button
+ can be used to undo the last entered digit. When a dyadic operation is
+ applied, the top value is used as~y. The \Key {grow} {grow} key toggles
+ between two different visualizations of the stack.
+
+ The stack is considerably larger than the screen representation suggests. In
+ the rare occasion that one encounters the message {\ss exhausted}, the amount
+ of stack entries already has totaled far beyond \MinLevel\ and one probably
+ already has forgotten what the values first entered represent.
+
+ The right column of fields reports the statistic calculations. By clicking on
+ the tag, one pushes the value on the Stack. The lower buttons are used to
+ reset~(\Key {new} {newn}), enter~(\Key {+} {addn}) and remove~(\Key {--}
+ {subn}) values to be taken into account when calculating those statistics.
+
+ This document is produced by \ConTeXt, a macro package written in \TeX. The
+ graphics are METAPOST graphics. The graphics, the PDF objects and the form
+ fields as well as JavaScript code were generated and inserted at run time.
+ Originally we used PDF\TeX\ and \MKII\ to process this document but this one
+ is done by \LUATEX\ and \MKIV. We kept the design and code original so that
+ it reflects how things were done (for readability we updated some \TEX\
+ definitions).
+
+ \stop
+
+ \vfilll
+
+ \startMPrun
+ logo_type := 302 ; % force single logo type
+ mpgraph := 302 ; % and use this number
+ input mp-prag ; % calculate logo of type
+ \stopMPrun
+
+ \startlinecorrection
+ \midaligned{\externalfigure[mprun.302][height=1.5cm]}
+ \stoplinecorrection
+
+ \midaligned{\strut Hans Hagen, PRAGMA ADE, \ConTeXt\ 18/2/1998--25/9/2018}
+
+ \blank
+
+ \midaligned{\strut\url[pragma-mail]}
+
+\stopstandardmakeup
+
+\starttexdefinition unexpanded BackgroundButton
+ \button [
+ background=screen,
+ backgroundscreen=.8,
+ backgroundoffset=5pt,
+ height=\vsize,
+ width=\hsize
+ ] {
+ } [
+ firstpage
+ ]
+\stoptexdefinition
+
+\starttexdefinition unexpanded ShowInfo #1#2
+ \startstandardmakeup
+ \pagereference[info:#1]
+ \vfill
+ \hbox to \hsize \bgroup
+ \hss
+ \useMPgraphic{#1}
+ \hss
+ \egroup
+ \blank[2*big]
+ \midaligned{#2}
+ \vfill
+ \stopstandardmakeup
+\stoptexdefinition
+
+\startMPinclusions
+
+ path ax, ay, p[] ;
+ color c ; c := \MPcolor{action} ;
+ pmax := 0 ;
+
+ let normalpow = pow ;
+
+ def draw_function (text fun) (expr xmin, xmax, xstep) =
+ pmax := pmax+1 ;
+ p[pmax] := for x=xmin step xstep until xmax:
+ (x,fun(x)) ..
+ endfor (xmax,fun(xmax)) ;
+ enddef ;
+
+ def draw_axis = % should sort of snap, to-do
+ pickup pencircle scaled 0 ;
+ for i=1 upto pmax:
+ draw p[i] ;
+ endfor ;
+ xmin := xpart llcorner currentpicture ;
+ xmax := xpart urcorner currentpicture ;
+ ymin := ypart llcorner currentpicture ;
+ ymax := ypart urcorner currentpicture ;
+ ax := (xmin,0)--(0,0)--(xmax,0) ;
+ ay := (0,ymin)--(0,0)--(0,ymax) ;
+ currentpicture := nullpicture ;
+ sx := 400/(xmax-xmin) ;
+ sy := 250/(ymax-ymin) ;
+ pickup pencircle xscaled (10/sx) yscaled (10/sy) ;
+ draw ax withcolor .4white ;
+ draw ay withcolor .4white ;
+ for i=1 upto pmax:
+ draw p[i] withcolor c ;
+ endfor ;
+ currentpicture := currentpicture xscaled sx yscaled sy ;
+ pmax := 0 ;
+ enddef ;
+
+\stopMPinclusions
+
+\startuseMPgraphic{sin}
+ draw_function(sind)(-360,360,60) ; draw_axis ;
+\stopuseMPgraphic
+
+\ShowInfo{sin}{Calculate the sine of the topmost stack entry.}
+
+\startuseMPgraphic{cos}
+ draw_function(cosd)(-360,360,60) ; draw_axis ;
+\stopuseMPgraphic
+
+\ShowInfo{cos}{Calculate the cosine of the topmost stack entry.}
+
+\startuseMPgraphic{tan}
+ draw_function(tand)(-240,-120,30) ;
+ draw_function(tand)( -60, 60,30) ;
+ draw_function(tand)( 120, 240,30) ;
+ draw_axis ;
+\stopuseMPgraphic
+
+\ShowInfo{tan}{Calculate the tangent of the topmost stack entry.}
+
+\startuseMPgraphic{asin}
+ draw_function(asin)(-1,1,.2) ; draw_axis ;
+\stopuseMPgraphic
+
+\ShowInfo{asin}{Calculate the arcsine of the topmost stack entry.}
+
+\startuseMPgraphic{acos}
+ draw_function(acos)(-1,1,.2) ; draw_axis ;
+\stopuseMPgraphic
+
+\ShowInfo{acos}{Calculate the arccosine of the topmost stack entry.}
+
+\startuseMPgraphic{atan}
+ draw_function(atan)(-1,1,.2) ; draw_axis ;
+\stopuseMPgraphic
+
+\ShowInfo{atan}{Calculate the arctangent of the topmost stack entry.}
+
+\startuseMPgraphic{sqr}
+ draw_function(sqr)(-3,3,1) ; draw_axis ;
+\stopuseMPgraphic
+
+\ShowInfo{sqr}{Calculate the square of the topmost stack entry.}
+
+\startuseMPgraphic{sqrt}
+ draw_function(sqrt)(0,5,1) ; draw_axis ;
+\stopuseMPgraphic
+
+\ShowInfo{sqrt}{Calculate the square root of the topmost stack entry.}
+
+\startuseMPgraphic{exp}
+ draw_function(exp)(0,5,1) ; draw_axis ;
+\stopuseMPgraphic
+
+\ShowInfo{exp}{Calculate the exponential function of the topmost stack entry.}
+
+\startuseMPgraphic{ln}
+ draw_function(ln)(0,50,5) ; draw_axis ;
+\stopuseMPgraphic
+
+\ShowInfo{ln}{Calculate the natural logaritm of the topmost stack entry.}
+
+\startuseMPgraphic{pow}
+ vardef mypow(expr n) = 3**n enddef ;
+ draw_function(mypow)(-3,3,.5) ; draw_axis ;
+\stopuseMPgraphic
+
+\ShowInfo{pow}{Calculate x\high{y} where y is the topmost stack entry.}
+
+\startuseMPgraphic{inv}
+ draw_function(inv)(-10,10,1) ; draw_axis ;
+\stopuseMPgraphic
+
+\ShowInfo{inv}{Calculate 1/x using the topmost stack entry.}
+
+\startMPinclusions
+
+ def draw_statistics (expr ShowNew, ShowAdd, ShowSubtract, ShowN, ShowSum, ShowMin, ShowMax, ShowMean, ShowSdev) =
+ color c ; c := \MPcolor{action} ;
+ Delta := 20 ;
+ Total := 100 ;
+ Range := 24 ;
+ Sum := 0 ;
+ Sqr := 0 ;
+ randomseed := .5 ;
+ pickup pencircle scaled .5Delta ;
+ for r := 0 upto Range:
+ Value[r] := 0 ;
+ endfor ;
+ for i=1 upto Total:
+ r := uniformdeviate 1 ;
+ Sum := Sum + r ;
+ Sqr := Sqr + r*r ;
+ r := round(r*Range) ;
+ Value[r] := Value[r]+1 ;
+ endfor ;
+ Mean := Sum/Total ;
+ Sdev := sqrt((Sqr-2*Sum*Mean+Total*Mean*Mean)/Total) ;
+ Mean := Mean*Range ;
+ Sdev := Sdev*Range ;
+ SdevMin := Mean-Sdev ;
+ SdevMax := Mean+Sdev ;
+ for r := 0 upto Range:
+ draw (r*Delta,0)--(r*Delta,Value[r]*Delta)
+ withcolor
+ if (ShowSdev and (r>SdevMin) and (r<SdevMax)) or ShowSum or
+ (ShowMin and (r=0)) or (ShowMax and (r=Range)) or
+ (ShowMean and (r=round(Mean)) or ShowSubtract) :
+ c
+ else :
+ .4white
+ fi ;
+ if ShowN:
+ draw (r*Delta,0) withcolor c
+ fi ;
+ endfor ;
+ if ShowAdd or ShowNew:
+ pushboundingbox currentpicture ;
+ currentpicture := nullpicture ;
+ for r := 0 upto Range:
+ draw (r*Delta,0) withcolor .4white ;
+ endfor ;
+ if ShowAdd:
+ draw (5*Delta,0) withcolor c ;
+ fi ;
+ popboundingbox currentpicture ;
+ elseif ShowSubtract:
+ draw (5*Delta,0) withcolor .4white ;
+ fi ;
+ enddef ;
+
+\stopMPinclusions
+
+\startuseMPgraphic{addn}
+ draw_statistics (false, true, false, false, false, false, false, false, false) ;
+\stopuseMPgraphic
+
+\ShowInfo{addn}{Add an observation to the statistics.}
+
+\startuseMPgraphic{subn}
+ draw_statistics (false, false, true, false, false, false, false, false, false) ;
+\stopuseMPgraphic
+
+\ShowInfo{subn}{Remove an observation from the statistics.}
+
+\startuseMPgraphic{newn}
+ draw_statistics (true, false, false, false, false, false, false, false, false) ;
+\stopuseMPgraphic
+
+\ShowInfo{newn}{Reset the statistics.}
+
+\startuseMPgraphic{sn}
+ draw_statistics (false, false, false, true, false, false, false, false, false) ;
+\stopuseMPgraphic
+
+\ShowInfo{sn}{Push the number of observations to the stack.}
+
+\startuseMPgraphic{stotal}
+ draw_statistics (false, false, false, false, true, false, false, false, false) ;
+\stopuseMPgraphic
+
+\ShowInfo{stotal}{Push the sum of encountered values to the stack.}
+
+\startuseMPgraphic{smin}
+ draw_statistics (false, false, false, false, false, true, false, false, false) ;
+\stopuseMPgraphic
+
+\ShowInfo{smin}{Push the lowest encountered value to the stack.}
+
+\startuseMPgraphic{smax}
+ draw_statistics (false, false, false, false, false, false, true, false, false) ;
+\stopuseMPgraphic
+
+\ShowInfo{smax}{Push the highest encountered value to the stack.}
+
+\startuseMPgraphic{smean}
+ draw_statistics (false, false, false, false, false, false, false, true, false) ;
+\stopuseMPgraphic
+
+\ShowInfo{smean}{Push the mean value to the stack.}
+
+\startuseMPgraphic{ssdev}
+ draw_statistics (false, false, false, false, false, false, false, false, true) ;
+\stopuseMPgraphic
+
+\ShowInfo{ssdev}{Push the standard deviation to the stack.}
+
+\startMPinclusions
+
+ def draw_ranges (expr ShowNegate, ShowCeiling, ShowFloor, ShowRound, ShowMin, ShowMax, ShowE) =
+
+ color c ; c := \MPcolor{action} ;
+
+ Tics := 5 ;
+ Gap := 5Tics ;
+ Height := .5Gap ;
+ Place := 3 ;
+
+ pickup pencircle scaled 10 ;
+
+ for i=-Tics upto Tics:
+ draw (i*Gap,-Height)--(i*Gap,Height) withcolor .4white ;
+ endfor ;
+
+ draw (-Tics*Gap,0)--(Tics*Gap,0) withcolor .4white ;
+ draw (0,-2Height)--(0,2Height) withcolor .4white ;
+
+ z1 = (Place*Gap,0) ;
+ z2 = ((Place+1)*Gap,0) ;
+
+ if ShowNegate:
+ draw (x1,-Height)--(x1,Height) withcolor c ;
+ draw (-x1,-0)--(-x1,0) withcolor c ;
+ elseif ShowCeiling:
+ draw (x2,-Height)--(x2,Height) withcolor c ;
+ linecap := butt ;
+ draw z1--z2 withcolor c ;
+ elseif ShowFloor:
+ draw (x1,-Height)--(x1,Height) withcolor c ;
+ linecap := butt ;
+ draw z1--z2 withcolor c ;
+ elseif ShowRound:
+ draw (x2,-Height)--(x2,Height) withcolor c ;
+ linecap := butt ;
+ draw .5[z1,z2]--z2 withcolor c ;
+ elseif ShowMin:
+ draw (x1,-Height)--(x1,Height) withcolor c ;
+ draw (x2,0)--(x2,0) withcolor c ;
+ elseif ShowMax:
+ draw (x2,-Height)--(x2,Height) withcolor c ;
+ draw (x1,0)--(x1,0) withcolor c ;
+ elseif ShowE:
+ e := Gap*mexp256 ;
+ draw (e,-3Height)--(e,3Height) withcolor c ;
+ fi ;
+
+enddef ;
+
+\stopMPinclusions
+
+\startuseMPgraphic{neg}
+ draw_ranges (true, false, false, false, false, false, false) ;
+\stopuseMPgraphic
+
+\ShowInfo{neg}{Negate the topmost stack entry.}
+
+\startuseMPgraphic{ceil}
+ draw_ranges (false, true, false, false, false, false, false) ;
+\stopuseMPgraphic
+
+\ShowInfo{ceil}{Set the topmost stack entry to the next integer.}
+
+\startuseMPgraphic{floor}
+ draw_ranges (false, false, true, false, false, false, false) ;
+\stopuseMPgraphic
+
+\ShowInfo{floor}{Set the topmost stack entry to the previous integer.}
+
+\startuseMPgraphic{round}
+ draw_ranges (false, false, false, true, false, false, false) ;
+\stopuseMPgraphic
+
+\ShowInfo{round}{Set the topmost stack entry to the nearest integer.}
+
+\startuseMPgraphic{min}
+ draw_ranges (false, false, false, false, true, false, false) ;
+\stopuseMPgraphic
+
+\ShowInfo{min}{Take the minumum of the two topmost stack entries.}
+
+\startuseMPgraphic{max}
+ draw_ranges (false, false, false, false, false, true, false) ;
+\stopuseMPgraphic
+
+\ShowInfo{max}{Take the maximum of the two topmost stack entries.}
+
+\startuseMPgraphic{e}
+ draw_ranges (false, false, false, false, false, false, true) ;
+\stopuseMPgraphic
+
+\ShowInfo{e}{Push 2.71828182845905 onto the stack.}
+
+\startuseMPgraphic{pi}
+ pickup pencircle scaled 10 ;
+ draw fullcircle scaled 150 withcolor .4white ;
+ linecap := butt ;
+ ahlength := 25 ;
+ drawarrow halfcircle scaled 150 withcolor \MPcolor{action} ;
+\stopuseMPgraphic
+
+\ShowInfo{pi}{Push 3.14159265358979 onto the stack.}
+
+\startMPinclusions
+
+ def draw_degrees(expr DrawInner, DrawOuter) =
+ pickup pencircle scaled .02 ;
+ path p ; p := fullcircle ;
+ path q ; q := subpath(0,1) of fullcircle ;
+ path r ; r := (0,0)--q--(0,0)--cycle ;
+ filldraw p withcolor .4white ;
+ filldraw r withcolor \MPcolor{action} ;
+ ahlength := .04 ;
+ if DrawInner:
+ drawarrow q scaled .30 withcolor .4white ;
+ elseif DrawOuter:
+ drawarrow q scaled .90 withcolor .4white ;
+ fi ;
+ currentpicture := currentpicture scaled 200 ;
+ enddef ;
+
+\stopMPinclusions
+
+\startuseMPgraphic{deg}
+ draw_degrees (true, false)
+\stopuseMPgraphic
+
+\ShowInfo{deg}{Convert radians into degrees.}
+
+\startuseMPgraphic{rad}
+ draw_degrees (false, true)
+\stopuseMPgraphic
+
+\ShowInfo{rad}{Convert degrees into radians.}
+
+\startuseMPgraphic{random}
+
+ pickup pencircle scaled 5 ;
+ color c ; c := \MPcolor{action} ;
+ draw unitsquare scaled 100 withcolor .4white ;
+ for i=1 upto 250:
+ draw (uniformdeviate 90, uniformdeviate 90)
+ shifted (5,5) withcolor (.4+uniformdeviate .6)*c ;
+ endfor ;
+ currentpicture := currentpicture scaled 2 ;
+
+\stopuseMPgraphic
+
+\ShowInfo{random}{Generate a random number in the range 0--1.}
+
+\startMPinclusions
+
+ def do_draw_number (expr n, drift, s, c) =
+ numeric Height, Delta, Drift, x_max, y_max, x_pos, y_pos ;
+ Height := 11 ;
+ Delta := 5 ;
+ Drift := if drift: 1.5 else: 0 fi ;
+ x_max := 8 ;
+ def d = (uniformdeviate Drift) enddef ;
+ if n=0:
+ draw ((-d-4.5Delta,d)--(+d-0.5Delta,Height-d))
+ withpen pencircle scaled 2
+ withcolor c ;
+ else:
+ for i := 1 upto n :
+ x_pos := ((i-1) mod (5*x_max))*Delta ;
+ y_pos := ((i-1) div (5*x_max))*(Height+Delta) ;
+ draw
+ if (i mod 5)=0 :
+ ((-d-4.5Delta,d)--(+d-0.5Delta,Height-d))
+ else :
+ ((-d,+d)--(+d,Height-d))
+ fi
+ shifted (x_pos,-y_pos)
+ withpen pencircle scaled 2
+ withcolor c ;
+ endfor ;
+ fi ;
+ currentpicture := currentpicture scaled s ;
+ enddef ;
+
+ def draw_number (expr n, s) =
+ do_draw_number(n,false,s,\MPcolor{keyboard}) ;
+ push_boundingbox currentpicture ;
+ currentpicture := nullpicture ;
+ do_draw_number(n,true,s,\MPcolor{keyboard}) ;
+ pop_boundingbox currentpicture ;
+ enddef ;
+
+\stopMPinclusions
+
+\dostepwiserecurse {0}{9}{1} {
+ \startuseMPgraphic{\recurselevel}
+ draw_number(\recurselevel,10)
+ \stopuseMPgraphic
+ \expanded {
+ \ShowInfo
+ {\recurselevel}
+ {Add a digit \recurselevel\ to the current stack entry.}%
+ }
+}
+
+\startuseMPgraphic{fac}
+
+ def facultate (expr n) =
+ if n=1: 1 else: n*facultate(n-1) fi
+ enddef ;
+ picture pic[] ;
+ for m := 1 upto 5:
+ do_draw_number(facultate(m),true,1,\MPcolor{action}) ;
+ pic[m] := currentpicture ;
+ currentpicture := nullpicture ;
+ endfor ;
+ xmax := xpart urcorner pic[5] - xpart llcorner pic[5] ;
+ for m = 1 upto 5:
+ xmin := xpart urcorner pic[m] - xpart llcorner pic[m] ;
+ addto currentpicture also pic[m] shifted (.5(xmax-xmin),-m*25) ;
+ endfor ;
+ currentpicture := currentpicture scaled 2 ;
+
+\stopuseMPgraphic
+
+\ShowInfo{fac}{Calculate the recursive multiplication of n, n--1, n--2, etc.}
+
+\startMPinclusions
+
+ def draw_template (expr ShowSign, ShowPeriod, ShowExponent, ShowDel) =
+ pickup pencircle scaled 10 ;
+ color ca ; ca := if (ShowDel): .4white else: \MPcolor{stack} fi ;
+ color cb ; cb := \MPcolor{keyboard} ;
+ Delta := 20 ;
+ Width := 10 ;
+ Position := 6 ;
+ Max := 15 ;
+ path p ; p := (0,0)--(Width,0) ;
+ draw (-2Width,0)--(0,0) withcolor if ShowSign: cb else: ca fi ;
+ for i=1 upto Position-1:
+ draw p shifted (i*Delta,0) withcolor ca ;
+ endfor ;
+ draw (Position*Delta+.5Width,0)
+ withcolor if ShowPeriod: cb else: ca fi ;
+ for i=Position+1 upto Max:
+ if i=Max-3:
+ draw ((Width,0)--(0,0)--(0,2Width)--(Width,2Width))
+ shifted (i*Delta,-2.5)
+ withpen pencircle scaled 5
+ withcolor if ShowExponent: cb else: ca fi ;
+ draw ((0,Width)--(Width,Width))
+ shifted (i*Delta,-2.5)
+ withpen pencircle scaled 5
+ withcolor if ShowExponent: cb else: ca fi ;
+ else:
+ draw p shifted (i*Delta,0) withcolor ca ;
+ fi ;
+ endfor ;
+ enddef ;
+
+\stopMPinclusions
+
+\startuseMPgraphic{sign}
+ draw_template(true, false, false, false) ;
+\stopuseMPgraphic
+
+\ShowInfo{sign}{Add a sign to the current stack entry.}
+
+\startuseMPgraphic{period}
+ draw_template(false, true, false, false) ;
+\stopuseMPgraphic
+
+\ShowInfo{period}{Add a period to the current stack entry.}
+
+\startuseMPgraphic{E}
+ draw_template(false, false, true, false) ;
+\stopuseMPgraphic
+
+\ShowInfo{E}{Start setting the exponent part of the current stack entry.}
+
+\startuseMPgraphic{del}
+ draw_template(false, false, false, true) ;
+\stopuseMPgraphic
+
+\ShowInfo{del}{Delete the last entered digit of the current stack entry.}
+
+\startMPinclusions
+
+ u := 50 ;
+ logo_type := 0 ;
+ input mp-prag ;
+ set_phead(u) ;
+
+ def draw_memory (expr DrawErase, DrawAdd, DrawSubtract, DrawCopy) =
+ pickup pencircle scaled .1u ;
+ color ca ; ca := \MPcolor{stack} ;
+ color cb ; cb := \MPcolor{keyboard} ;
+ draw phead withcolor .4white ;
+ if DrawErase:
+ stripe_path_n
+ (withcolor .4white)
+ (fill) pbrain scaled .8 shifted (.5u,.5u) withcolor .8cb ;
+ else:
+ fill pbrain scaled .8 shifted (.5u,.5u)
+ if DrawCopy: withcolor .8ca else: withcolor .8cb fi ;
+ fi ;
+ draw pbrain scaled .8 shifted (.5u,.5u) withcolor cb ;
+ push_boundingbox currentpicture ;
+ ahlength:=.2u ;
+ path drain ; drain := (4.5u,2u){dir 120}..(2.25u,2.75u) ;
+ if DrawAdd:
+ drawarrow drain withcolor ca ;
+ elseif DrawSubtract or DrawCopy:
+ drawarrow reverse drain withcolor ca ;
+ fi ;
+ pop_boundingbox currentpicture ;
+ enddef ;
+
+\stopMPinclusions
+
+\startuseMPgraphic{newmem}
+ draw_memory (true,false,false,false) ;
+\stopuseMPgraphic
+
+\ShowInfo{newmem}{Erase the memory buffer.}
+
+\startuseMPgraphic{addmem}
+ draw_memory (false,true,false,false) ;
+\stopuseMPgraphic
+
+\ShowInfo{addmem}{Add to the memory buffer.}
+
+\startuseMPgraphic{submem}
+ draw_memory (false,false,true,false) ;
+\stopuseMPgraphic
+
+\ShowInfo{submem}{Substract from the memory buffer.}
+
+\startuseMPgraphic{copmem}
+ draw_memory (false,false,false,true) ;
+\stopuseMPgraphic
+
+\ShowInfo{copmem}{Copy the memory buffer to the stack.}
+
+\startMPinclusions
+
+ def erase_stack =
+ stripe_path_n
+ (withcolor .4white)
+ (fill) p withcolor .8cb ;
+ enddef ;
+
+ def draw_stack (expr ShowNew, ShowPush, ShowPop, ShowDup) =
+ path p ;
+ color ca ; ca := \MPcolor{stack} ;
+ color cb ; cb := \MPcolor{keyboard} ;
+ for i=8 downto 1:
+ j := i-1 ;
+ pickup pencircle scaled 1.5 ;
+ p := unitsquare
+ shifted(-.5,-.5)
+ xscaled 100 yscaled 40
+ shifted(20*j,j*15)
+ scaled (1-j*.04) ;
+ if i<3:
+ fill p withcolor .4white ;
+ elseif ShowPush:
+ fill p withcolor if i=3: .8cb else : .8ca fi ;
+ elseif ShowPop:
+ if i=3: erase_stack else: fill p withcolor .8ca fi ;
+ elseif ShowNew:
+ erase_stack ;
+ elseif ShowDup:
+ fill p withcolor if i>4: .8ca else: .8cb fi ;
+ else:
+ fill p withcolor .4white ;
+ fi ;
+ draw p withcolor ca ;
+ endfor ;
+ currentpicture := currentpicture scaled 1.5 ;
+ enddef ;
+
+\stopMPinclusions
+
+\startuseMPgraphic{push}
+ draw_stack (false, true, false, false)
+\stopuseMPgraphic
+
+\ShowInfo{push}{Push a new entry to the stack.}
+
+\startuseMPgraphic{pop}
+ draw_stack (false, false, true, false)
+\stopuseMPgraphic
+
+\ShowInfo{pop}{Remove the topmost entry from the stack.}
+
+\startuseMPgraphic{new}
+ draw_stack (true, false, false, false)
+\stopuseMPgraphic
+
+\ShowInfo{new}{Erase the whole stack.}
+
+\startuseMPgraphic{dup}
+ draw_stack (false, false, false, true)
+\stopuseMPgraphic
+
+\ShowInfo{dup}{Duplicate the topmost stack entry.}
+
+\startMPinclusions
+
+ def draw_funcalc (expr p, q, r, action) =
+
+ color b ; b := \MPcolor{keyboard} ;
+ color c ; c := \MPcolor{stack} ;
+
+ draw ((-2.25max(p,q,r))-1,0)--(-1,0) withcolor .4white ;
+
+ pickup pencircle scaled 2 ;
+ for i=1 upto p: draw (-i*2.25, 3.75) withcolor c ; endfor ;
+ for i=1 upto q: draw (-i*2.25, 1.50) withcolor c ; endfor ;
+ for i=1 upto r: draw (-i*2.25,-1.50) withcolor c ; endfor ;
+ pickup pencircle scaled .5 ;
+
+ push_boundingbox currentpicture ;
+
+ pair w ; w := (1.125,0) ;
+ path ww ; ww := -w -- w ;
+
+ if action=1:
+ draw ww shifted w withcolor b ;
+ draw ww rotated 90 shifted w withcolor b ;
+ elseif action=2:
+ draw ww shifted w withcolor b ;
+ elseif action=3:
+ draw ww rotated 45 shifted w withcolor b ;
+ draw ww rotated 135 shifted w withcolor b ;
+ elseif action=4:
+ draw ww rotated 45 shifted w withcolor b ;
+ fi ;
+
+ pop_boundingbox currentpicture ;
+
+ currentpicture := currentpicture scaled 15 ;
+
+ enddef ;
+
+\stopMPinclusions
+
+\startuseMPgraphic{add}
+ draw_funcalc (6, 6, 7, 1)
+\stopuseMPgraphic
+
+\ShowInfo{add}{Add the two topmost stack entries.}
+
+\startuseMPgraphic{sub}
+ draw_funcalc (5, 4, 5, 2)
+\stopuseMPgraphic
+
+\ShowInfo{sub}{Subtract the topmost stack entry from the one below.}
+
+\startuseMPgraphic{mul}
+ draw_funcalc (3, 4, 7, 3)
+\stopuseMPgraphic
+
+\ShowInfo{mul}{Multiply the two topmost stack entries.}
+
+\startuseMPgraphic{div}
+ draw_funcalc (5, 2, 4, 4)
+\stopuseMPgraphic
+
+\ShowInfo{div}{Divide the pre-last stack entry by the topmost one.}
+
+\startuseMPgraphic{grow}
+
+ pickup pencircle scaled 5 ;
+ ahlength := 10 ;
+
+ path p ; p := (0,0)--(60,0) ;
+ path q ; q := (30,2*15)--(30,7*15) ;
+ path r ; r := (30,0)--(30,7*15) ;
+
+ for i=0 upto 7:
+ draw p shifted (0,i*15) withcolor
+ if i<3: \MPcolor{stack} else: .4white fi ;
+ endfor ;
+
+ addto currentpicture also currentpicture
+ rotatedaround (center currentpicture, 180)
+ shifted (90, 0) ;
+
+ drawarrow q withcolor \MPcolor{keyboard} ;
+ drawarrow reverse r shifted (90, 0) withcolor \MPcolor{keyboard} ;
+
+ currentpicture := currentpicture scaled 2 ;
+
+\stopuseMPgraphic
+
+\ShowInfo{grow}{Toggle grow mode, another way of stacking.}
+
+\startuseMPgraphic{exit}
+
+ path p ; p := (100,30)--(100,0)--(0,0)--(0,100)--(100,100)--(100,70) ;
+ pickup pencircle scaled 10 ;
+ linecap := butt ;
+ ahlength := 60 ;
+ ahangle := 75 ;
+ filldraw
+ p--cycle
+ withcolor \MPcolor{action} ;
+ draw
+ p
+ withcolor \MPcolor{stack} ;
+ push_boundingbox currentpicture ;
+ pickup pencircle scaled 30 ;
+ draw
+ center currentpicture --
+ (xpart lrcorner currentpicture+.75ahlength, ypart center currentpicture)
+ withcolor \MPcolor{keyboard} ;
+ pickup pencircle scaled 5 ;
+ drawarrow
+ center currentpicture --
+ (xpart lrcorner currentpicture, ypart center currentpicture)
+ withcolor \MPcolor{keyboard} ;
+ pop_boundingbox currentpicture ;
+ currentpicture := currentpicture scaled 1.75 ;
+
+\stopuseMPgraphic
+
+\ShowInfo{exit}{Close this document.}
+
+\stoptext
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-01 16:34:52 +0000