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histogrammer.r

REBOL [ File: %histogrammer.r Date: 15-Apr-2011 Title: "Histogram maker" Purpose: {To produce a histogram from a data series, to display it in a window, to save it as PNG file and/or as a data file} Author: "Rudolf W. Meijer" Home: http://users.telenet.be/rwmeijer E-mail: %rudolf--meijer--telenet--be Version: 1.0.0 Comment: "Needs RebGUI (http://www.dobeash.com/rebgui.html)" History: [ 0.1.0 [9-Apr-2011 {Start of project} "RM"] 1.0.0 [15-Apr-2011 {First release} "RM"] ] Library: [ level: 'intermediate platform: 'all type: 'function domain: [scientific graphics] tested-under: [SDK 2.7.8 "Windows XP"] support: "Contact author by e-mail" license: { This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License (http://www.gnu.org/licenses) for more details. } ] ] ;---|----1----|----2----|----3----|----4----|----5----|----6----|----7----|- ctx-histo: context [ ; settable constants (parameters) bg-color: 255.255.240 ; background for histogram bar-color: gray ; color of histo bars ind-size: 960x480 ; indicative dimensions of histogram max-bar: 48 ; max width of bar ; "globals" rg-version: none ; set by call to make-histo ofile: none ; for Save and List options set 'make-histo func [ {Produces, displays and saves a histogram from a data series. Needs RebGUI (http://www.dobeash.com/rebgui.html).} h-data [block! string! binary!] {if a block, must be flat sequence of fixed size records; if a string or binary, may also have fixed size records.} rec-size [integer!] {the record size; length? h-data must be an integral multiple of rec-size} field-no [integer!] {the index of the field to be histogrammed; this must be of same type integer! or char! in all records; this condition is not checked! and may lead to errors} intval [integer!] {the size of a single interval} /title title-text [string!] {will be displayed on top} /size histo-size [pair!] {specify approx. size in pixels} /start start-val [integer! char!] {lowest value on x-axis} /local ; in order of appearance integral? text-size s-mold get-file cell-size nr-points sorted min-val max-val nr-bars histo limit h-size v-size max-freq v-scale o-magn vdiv-width field-height nr-vdiv v-div v-frac bar-width hdiv-width h-div hdiv-size vdiv-size window v-bias v-margin nth-vdiv v-pos tall nth-hdiv div-val nth-divval ][ integral?: func [n][n = to-integer n] text-size: func [v [integer! char!]][ case [ char? v [20 / cell-size] ; rare case of max-val = min-val = 0 v = 0 [12 / cell-size] ; normal case: non-zero integer true [ round/ceiling (8 * to-integer log-10 abs v) + 12 + (either negative? v [8][0]) / cell-size ] ] ] s-mold: func [v [integer! char!] /local m][ m: mold v if char? v [m: copy/part at m 3 back tail m] m] get-file: func [ext [file!] /local filter-text][ ; calling convention changed between 1xx and 2xx filter-text: join uppercase to-string next ext " files" either rg-version < 200 ; set immediately below [request-file/save/only/filter filter-text to-string join "*" ext] [request-file/save/title/filter filter-text ext] ] ; check that RebGUI is loaded ; --------------------------- either value? 'ctx-rebgui [ rg-version: ctx-rebgui/build ; used by getfile cell-size: ctx-rebgui/sizes/cell ][ alert "RebGUI missing! Get it from http://rebgui.codeplex.com" exit ] ; check settings and arguments ; ---------------------------- if any [ cell-size > 4 cell-size < 3 ][alert "Incorrect RebGUI settings! Check ctx-rebgui/sizes/cell = 3 or 4" exit] if any [ not tuple? bg-color not tuple? bar-color not pair? ind-size ind-size/x < 1 ind-size/y < 1 not integer? max-bar max-bar < 1 ][alert "Incorrect parameter settings! Check ctx-histo" exit] nr-points: length? h-data if any [ nr-points = 0 rec-size < 1 field-no < 1 intval < 1 field-no > rec-size not integral? nr-points / rec-size ][alert "Incorrect or empty input!" exit] ; compute histogram ; ----------------- ; first sort the data sorted: copy h-data sort/skip/compare sorted rec-size field-no sorted: at sorted field-no ; compute minimum and maximum value and number of bars min-val: first sorted if all [start (type? start-val) = (type? min-val)][ min-val: min start-val min-val ] max-val: pick sorted nr-points - rec-size + 1 nr-bars: 1 + to-integer max-val - min-val / intval ; initialize histogram histo: array/initial nr-bars 0 ; scan the data and tally the values ; intervals are closed on the left and open on the right limit: min-val + intval while [not tail? sorted][ either (first sorted) < limit [ change histo 1 + first histo sorted: skip sorted rec-size ][ histo: next histo limit: limit + intval ] ] histo: head histo ; make histogram (graph) in window ; -------------------------------- ; first compute the dimensions of the histogram display: either all [size (histo-size/x > 0) (histo-size/y > 0)] [h-size: to-integer histo-size/x / cell-size v-size: to-integer histo-size/y / cell-size] [h-size: to-integer ind-size/x / cell-size v-size: to-integer ind-size/y / cell-size] ; size of tallest bar, vertical scale factor and adjusted v-size ; for v-scale < 1, we round to nearest "nice" value: ; .5, .2, .1, .05, .02., .01, .005 etc. max-freq: first sort/reverse copy histo v-scale: v-size / max-freq either v-scale < 1 [ o-magn: 10 ** round/floor log-10 v-scale v-scale: o-magn * pick [1 1 2 2 2 5 5 5 5 5 5 5 5 5 10 10 10 10 10 10] to-integer 2 * v-scale / o-magn ][ v-scale: to-integer v-scale ] v-size: max-freq * v-scale vdiv-width: text-size max-freq ; height of text fields for divisions (title field is twice high) ; this may be set to between 12 and 20 without compromising the graph ; the smaller field-height, the closer the vertical divisions will ; be together field-height: to-integer 20 / cell-size ; nr-vdiv is max. number of vertical divisions that can be shown ; v-div is the step y-value shown at the divisions nr-vdiv: to-integer v-size / field-height v-div: max 1 to-integer max-freq / nr-vdiv o-magn: to-integer 10 ** to-integer log-10 v-div unless integral? v-frac: v-div / o-magn [ v-div: o-magn * to-integer v-frac + 1 ] ; actual bar width (limited to max-bar) bar-width: min to-integer max-bar / cell-size max 1 to-integer h-size / nr-bars ; size of division field on x axis hdiv-width: 8 / cell-size + either any [char? max-val (abs max-val) > (abs min-val)] [text-size max-val][text-size min-val] ; h-div is the step in x-values needed to make sure hdiv-width is ; available for the text field h-div: hdiv-width / bar-width unless integral? h-div [h-div: to-integer h-div + 1] vdiv-width: max vdiv-width hdiv-width hdiv-size: as-pair hdiv-width field-height vdiv-size: as-pair vdiv-width field-height ; compose the window for display window: make block! [ graph: panel bg-color data [] ] either all [title not empty? title-text] [ ; re-adjust graph sizes and insert the title text field h-size: nr-bars * bar-width + vdiv-width + (20 / cell-size) v-bias: 2 * field-height v-size: v-size + v-bias insert last window compose/deep [ at 0x0 text (as-pair h-size v-bias) (title-text) bold font [align: 'center size: 18] ] ][ v-bias: 0 ] v-margin: to-integer 12 / cell-size ; position the vertical (y-value) divisions ; the while condition guards against overlap of the highest y-value ; below max-freq with that of max-freq itself nth-vdiv: 0 while [(v-bias + v-margin) <= (v-pos: v-size - to-integer v-scale * nth-vdiv)][ insert tail last window compose [ at (as-pair 0 v-pos) text (vdiv-size) (to-string nth-vdiv) font [align: 'right] ] nth-vdiv: nth-vdiv + v-div ] ; insert y-value of tallest bar insert tail last window compose [ at (as-pair 0 v-bias) text (vdiv-size) (to-string max-freq) font [align: 'right] ] ; construct the bars and insert them repeat i nr-bars [ tall: to-integer v-scale * histo/:i unless histo/:i = 0 [tall: max 1 tall] insert tail last window compose [ at (as-pair i - 1 * bar-width + vdiv-width + 2 v-size - tall + v-margin) box (as-pair max 1 bar-width - 1 tall) (bar-color) ] ] ; show the horizontal (x-value) divisions nth-hdiv: 0 div-val: h-div * intval nth-divval: min-val while [nth-divval <= (max-val + div-val)][ insert tail last window compose [ at (as-pair nth-hdiv * bar-width + vdiv-width - hdiv-width + 3 v-size + v-margin) text (hdiv-size) (join s-mold nth-divval "|") font [align: 'right] ] nth-hdiv: nth-hdiv + h-div nth-divval: nth-divval + div-val ] ; insert the Save, List and Close buttons insert tail window [ return button "Save" [ either ofile: get-file %.png [save/png ofile to-image graph][exit] ] button "List" [ either ofile: get-file %.txt [save ofile head insert histo reduce [min-val intval]][exit] ] button "Close" [hide-popup] ] ; display the window to show the histogram ; ---------------------------------------- display/dialog "Histogrammer v. 1.0.0" window ] ; end make-histo ] ; end context-histo
halt ;; to terminate script if DO'ne from webpage
Notes
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  • (rudolf:meijer:telenet:be)