decksh
# decksh: a little language for presentations, visualizations, and information displays `decksh` is a domain-specific language (DSL) for generating [`deck`](https://github.com/ajstarks/deck) markup.  `decksh` elements ## Install ``` go get github.com/ajstarks/decksh # install the package go install github.com/ajstarks/decksh/cmd/decksh@latest # install the decksh command ``` The current version is 2026-06-10-1.1.0 ## References and Examples - [`decksh` overview](https://speakerdeck.com/ajstarks/decksh-a-little-language-for-decks) - [`decksh` object reference](https://speakerdeck.com/ajstarks/decksh-object-reference) - [Installing and Running decksh/pdfdeck](https://speakerdeck.com/ajstarks/pdfdeck) - [Repository of decksh projects and visualizations](https://github.com/ajstarks/deckviz "Repository of decksh projects and visualizations") ## Package use The `Process` function reads decksh commands from an `io.Reader` and writes deck markup to an `io.Writer`, returning an error. For example: ``` package main import ( "fmt" "os" "strings" "github.com/ajstarks/decksh" ) func main() { input := ` deck slide ctext "hello, world" 50 50 10 eslide edeck ` err := decksh.Process(os.Stdout, strings.NewReader(input)) if err != nil { fmt.Fprintf(os.Stderr, "%v\n", err) } } ``` Produces: ``` <deck> <slide> <text align="c" xp="50" yp="50" sp="10" >hello, world</text> </slide> </deck> ```` ## Running the command line client This repository also contains `cmd/decksh`, a client decksh command: `decksh` reads from the specified input, and writes deck markup to the specified output destination: ``` $ decksh # input from stdin, output to stdout $ decksh -o foo.xml # input from stdin, output to foo.xml $ decksh foo.sh # input from foo.sh output to stdout $ decksh -o foo.xml foo.sh # input from foo.sh output to foo.xml $ decksh -version # show decksh version $ decksh -dump ... # show decksh variables ``` Typically, `decksh` acts as the head of a rendering pipeline, where another `deck` client renders the markup. This example uses `pdfdeck` ``` $ decksh text.dsh | pdfdeck -stdout -pagesize 1200,900 - > text.pdf ``` ## Example input decksh hello, world: ``` // hello world deck slide "black" "white" ctext "hello world" 50 25 15 circle 0 0 120 "blue" eslide edeck ``` produces:  This deck script: ``` // Example deck midx=50 midy=50 iw=640 ih=480 imfile="follow.jpg" imlink="https://budnitzbicycles.com" imscale=58 dtop=87 opts="-fulldeck=f -textsize 1 -xlabel=2 -barwidth 1.5" deck slide "white" "black" ctext "Deck elements" midx dtop 5 cimage "follow.jpg" "Dreams" 72 midy iw ih imscale imlink textblock "Budnitz #1, Plainfield, NJ, May 10, 2015" 55 35 10 1 "serif" "white" // List blist 10 75 3 li "text, image, list" li "rect, ellipse, polygon" li "line, arc, curve" elist // Graphics gy=10 c1="red" c2="blue" c3="green" rect 15 gy 8 6 c1 ellipse 27.5 gy 8 6 c2 polygon "37 37 45" "7 13 10" c3 line 50 gy 60 gy 0.25 c1 arc 70 gy 10 8 0 180 0.25 c2 curve 80 gy 95 25 90 gy 0.25 c3 // Chart chleft=10 chright=45 chtop=42 chtbottom=28 dchart -left chleft -right chright -top chtop -bottom chbottom opts AAPL.d eslide edeck ``` Produces:  Text, font, color, caption and link arguments follow Go conventions (surrounded by double quotes). ## Coordinate System `decksh` (like the deck markup it produces) uses a traditional Cartesian coordinate system: The origin (0,0) is at the lower left, x increases to the right, and y increases upwards. The coordinate system is expliticly based on the percentages, with x and y ranging from 0-100. For example (50, 50) is the middle of the canvas, (100,100) is the upper right, (100,0) is the lower right, and (0,100) is the upper left.  ## Rulers Make rulers with an interval (default 5), with optional color ```ruler [increment] [color]```  ## Colors Colors formats are: - [RGB](https://en.wikipedia.org/wiki/RGB_color_model "RGB"): "rgb(n,n,n)", where n ranges from 0-255, for example "`"rgb(128,0,128)"` . - hex: "#rrggbb", for example `"#aa00aa"`, - [HSV](https://en.wikipedia.org/wiki/HSL_and_HSV "HSV"): hsv(hue,saturation,value), hue ranges from 0-360, saturation and value range from 0-100, for example `"hsv(360,30,30)"` (pdfdeck and pngdeck support this syntax) - [SVG color names](https://www.w3.org/TR/SVG11/types.html#ColorKeywords "SVG color names"). Color gradients (used for slide backgrounds and rectangle and square fills) are specified as color1/color2/percent, for example, `"blue/white/90"` ## Coordinates, dimensions, scales, opacity and fonts Coordinates, dimensions, scales and opacities are floating point numbers ranging from from 0-100 (representing percentages of the canvas width and percent opacity). Some arguments are optional, and if omitted defaults are applied (black for text, gray for graphics, 100% opacity). Canvas size and image dimensions are in pixels. Fonts may be: - "sans" - "serif" - "mono" - symbol"  ## Begin or end a deck. ``` deck edeck ``` ## Begin, end a slide with optional background and text colors. ``` slide [bgcolor] [fgcolor] eslide ``` Note that doc/edoc and page/epage are may also be used as synomyms for deck/edeck and slide/eslide. ## Specify the size of the canvas. ``` canvas w h ``` ## Simple assignments `id=<number>` defines a constant, which may be then subtitited. For example: ``` x=10 y=20 text "hello, world" x y 5 ``` The special identifier, `deckshVersion` contains the string denoting the version of decksh. ## Assignment operations `id+=<number>` increment the value of `id` by `<number>` ``` x+=5 ``` `id-=<number>` decrement the value of `id` by `<number>` ``` x-=10 ``` `id*=<number>` multiply the value of `id` by `<number>` ``` x*=50 ``` `id*=<number>` divide the value of `id` by `<number>` ``` x/=100 ``` ## Binary operations Addition `id=<id> + number or <id>` ``` tx=10 spacing=1.2 sx=tx-10 vx=tx+spacing ``` Subtraction `id=<id> - number or <id>` ``` a=x-10 ``` Muliplication `id=<id> * number or <id>` ``` a=x*10 ``` Division `id=<id> / number or <id>` ``` a=x/10 ``` Modulo `id=<id> % number or <id>` a=x%10 ## Coordinate assignments Assign (x,y) coordinates to the specified identifier. The x coordinate is `id_x` and the y coordinate is `id_y`. The expression with the parentheses may be a constant, variable or binary expression. This code: ``` a=40 b=40 c=20 p0=(50,50) p1=(a,b) p2=(a+c,b) p3=(a+c,b+c) p4=(a,b+c) circle p0_x p0_x 3 line p1_x p1_y p2_x p2_y 0.2 "blue" line p2_x p2_y p3_x p3_y 0.2 "red" line p3_x p3_y p4_x p4_y 0.2 "green" line p4_x p4_y p1_x p1_y 0.2 "orange" ``` makes this:  ## Polar Coordinates ``` x=polarx cx cy r theta y=polary cx cy r theta ``` Return the polar coordinate given the center at `(cx, cy)`, radius `r`, and angle `theta` (in degrees)  ## Polar Coordinates (composite) ``` p=polar cx cy r theta ``` Return the polar coordinates `(p_x)` and `(p_y)` given the center at `(cx, cy)`, radius `r`, and angle `theta` (in degrees) ## Dump The keyword `dump` causes a sorted list of variables and their values to be printed on standard error. For example, given: ``` deck slide x=50 y=50 s=5 message="Hello, decksh" ctext message x y s eslide dump edeck ``` Produces: ``` deckshVersion = "2024-12-15-1.0.0" message = "Hello, decksh" s = 5 x = 50 y = 50 ``` You can also specify that specific variables are shown, `dump x y` shows: ``` x = 50 y = 50 ``` ## Area ``` a=area d c=area a+b ``` return the circular area, `a` for the diameter `d`. ## Formatted Text Assign a string variable with formatted text (using package fmt floating point format strings). Up to five variables may be used. ``` w1=10 w2=20+100 s0=format "Widget 1: %.2f" w1 s1=format "Widget 2: %.3f" w2 st=format "Total Widgets: %v" s1+w2 ``` Large numbers may also be formatted with commas using the `%,` format string. For example: ``` s=format "%," 123456789 // s contains 123,456,789 ``` ## Random Number ``` x=random min max ```  assign a random number in the specified range ## Math Functions decksh supports these math functions: - cosine - sine - square root - tangent ### Cosine return the coine of the number of expression (`id` or binary operation) ``` a=4 b=10 x=cosine 4 x=cosine a+b x=cosine b ``` ### Sine return the sine of the number of expression (`id` or binary operation) ``` a=4 b=10 x=sine 4 x=sine a+b x=sine b ``` ### Square Root return the square root of the number of expression (`id` or binary operation) ``` a=4 b=10 x=sqrt 4 x=sqrt a+b x=sqrt b ``` ### Tangent return the square root of the number of expression (`id` or binary operation) ``` a=4 b=10 x=tangent 4 x=tangent a+b x=tangent b ``` ## Range Value Mapping ``` x=vmap v vmin vmax min max ```  For value `v`, map the range `vmin-vmax` to `min-max`. ## Substring ``` x=substr string begin end ``` assigns a substring given beginning and ending indicies. `-` may be used as a shorthand for the beginning and end. ``` s="hello, world" a=substr s - - // a="hello, world" b=substr s - 4 // b="hello" c=substr s 7 - // c="world" d=substr s 3 8 // d="lo, wo" e=substr "This is a test" 5 8 // e="is a" ``` ## Loops Loop over `statements`, with `x` starting at `begin`, ending at `end` with an optional `increment` (if omitted the increment is 1). Substitution of `x` occurs in statements. ``` for x=begin end [increment] statements efor ``` Loop over `statements`, with `x` ranging over the strings within `[]`. Substitution of `x` will occur in statements. ``` for x=["abc" "def" "ghi"] statements efor ``` Loop over `statements` with `x` ranging over the numbers within `()`. Substitution of `x` will occur in statements. ``` for x=(11 56 89 90 230) statements efor ``` Loop over `statements`, with `x` ranging over the contents `"file"`. Substitution of `x` will occur in statements. ``` for x="file" statements efor ``` ## Conditionals Specify the conditional execution of decksh statements with `if condition`, `else` and `eif`. The else block is optional. The values for ```v1``` and ```v2``` may be either numbers of strings. (For strings only ```==``` and ```!=``` apply). The conditions are: ``` if v1 condition v2 where condition is: == or eq equals if x == y != or ne not equals if x != y < or lt less than if x > y > or gt greater than if x < y >= or ge greater than or equal if x >= y <= or ge less than or equal if x <= y >< or bt between if x >< y z ``` For example: ``` x=10 y=20 if x > y text "x is greater than y" x y 5 else text "x is not greater than y" x y 5 eif ``` The else block may be omitted: ``` if x < 10 text "x is less than 10" x y 5 eif ``` For strings: ``` c1="red" c2="blue" if c1 != c2 text "red is not blue" 50 50 2 eif ``` ## Include decksh markup from a file ``` include "file" ``` places the contents of `"file"` inline. ## Functions Functions have a defined `name` and arguments, and are specifed with statements between the `def` and `edef` keywords ``` def name arg1 arg2 ... argn statements edef ``` ## Importing function defintions Functions may be imported once, and then called by name. For example, given a file `redcircle.dsh`: ``` def redcircle X Y circle X Y 10 "red" edef ``` which is referenced: ``` import "redcircle.dsh" x=50 y=50 x2=x-20 y2=y+20 redcircle x y redcircle x2 y2 ``` makes:  Functions may also be called with the `func` keyword: ``` func "file" arg1 ... argn ``` For example, given a file "ftest.dsh" ``` def ftest funx funy funs funt funs*=2 ctext funt funx funy funs edef ``` calling the function: ``` func "ftest.dsh" 50 30 2.5 "hello" ``` produces: ``` funx=50 funy=30 funs=5.0 funt="hello" ctext "hello" 50 30 5.0 ``` ## Data: Make a file ``` data "foo.d" uno 100 dos 200 tres 300 edata ``` makes a structured data file (name[tab]value) named `foo.d` with the lines between `data` and `edata`. If the optional argument "plain" is added, the file is copied directly (with whitespace trimmed from the beginning). ``` data "foo.txt" "plain" Now is the time for all good men to come to the aid of the party. edata ```` ## Grid: Place objects on a grid ``` grid "file.dsh" x y xskip yskip limit ```  The first file argument (`"file.dsh"` above) specifies a file with decksh commands; each item in the file must include the arguments "x" and "y". Normal variable substitution occurs for other arguments. For example if the contents of `file.dsh` has six items: ``` circle x y 5 circle x y 10 circle x y 15 square x y 5 square x y 10 square x y 15 ``` The line: ``` grid "file.dsh" 10 80 20 30 50 ``` creates two rows: three circles and then three squares `x, y` specify the beginning location of the items, `xskip` is the horizontal spacing between items. `yinternal` is the vertical spacing between items and `limit` the the horizontal limit. When the `limit` is reached, a new row is created. ## Text Left, centered, end, or block-aligned text or file contents (`x` and `y` are the text's reference point), with optional font ("sans", "serif", "mono", or "symbol"), color and opacity. ### left-aligned text ``` text "text" x y size [font] [color] [opacity] [link] btext "text" x y size [font] [color] [opacity] [link] ```  ### centered text ``` ctext "text" x y size [font] [color] [opacity] [link] ```  ### right-aligned text ``` etext "text" x y size [font] [color] [opacity] [link] ```  ### a text block (from either a string or the contents of a file) ``` textblock "text" x y width size [font] [color] [opacity] [link] textblockfile "filename" x y width size [font] [color] [opacity] [link] ```  ### paragraphs ``` para x y width size [font] [color] [opacity] [link] .... epara ````  Text rotated along the specified angle (in degrees) ``` rtext "text" x y angle size [font] [color] [opacity] [link] ``` ### rotated text  ### text on an arc Text on an arc centered at `(x,y)`, with specified radius, between begin and ending angles (in degrees). if the beginning angle is less than the ending angle the text is rendered counter-clockwise. if the beginning angle is greater than the ending angle, the text is rendered clockwise. ``` arctext "text" x y radius begin-angle end-angle size [font] [color] [opacity] [link] ```  ### text from file contents (plain and code formatted) Place the contents of "filename" at (x,y). Place the contents of "filename" in gray box, using a monospaced font. ``` textfile "filename" x y size [font] [color] [opacity] [linespacing] ```  ``` textcode "filename" x y width size [color] ```  ## Images Plain and captioned, with optional scales, links and caption size. `(x, y)` is the center of the image, and `width` and `height` are the image dimensions in pixels. ``` image "file" x y width height [scale] [link] cimage "file" "caption" x y width height [scale] [link] [size] ```  ## Lists (plain, bulleted, numbered, centered). Optional arguments specify the color, opacity, line spacing, link and rotation (degrees) ``` list x y size [font] [color] [opacity] [linespacing] [link] [rotation] ```  ``` blist x y size [font] [color] [opacity] [linespacing] [link] [rotation] ```  ``` nlist x y size [font] [color] [opacity] [linespacing] [link] [rotation] ```  ``` clist x y size [font] [color] [opacity] [linespacing] [link] [rotation] ```  ### list items, and ending the list ``` li "text" elist ``` ## Graphics Rectangles, ellipses, squares, circles: specify the center location `(x, y)` and dimensions `(w,h)` with optional color and opacity. The default color and opacity is gray, 100%. In the case of the `acircle` keyword, the `a` argument is the area, not the diameter. ``` rect x y w h [color] [opacity] ellipse x y w h [color] [opacity] ```   ``` square x y w [color] [opacity] circle x y w [color] [opacity] ```   ``` acircle x y a [color] [opacity] ```  Rounded rectangles are similar, with the added radius for the corners: (solid colors only) ``` rrect x y w h r [color] ```  For polygons, specify the x and y coordinates as a series of numbers, with optional color and opacity. ``` polygon "xcoords" "ycoords" [color] [opacity] ```  Note that the coordinates may be either discrete: ``` polygon "10 20 30" "50 60 50" ``` or use substitution: ``` x1=10 x2=20 x3=30 y1=50 y2=y1+10 y3=y1 polygon "x1 x2 x3" "y1 y2 y3" ``` A combination of constants and substitution is also allowed. ``` polygon "20 x2 30" "50 y2 50" ``` Polyline is similar to polygon, except line segments are used instead of a filled polygon, and you may specify a line width. ``` polyline "xcoords" "ycoords" [lw] [color] [opacity] ```  For lines, specify the coordinates for the beginning `(x1,y1)` and end points `(x2, y2)`. For horizontal and vertical lines specify the initial point and the length. Line thickness, color and opacity are optional, with defaults (0.2, gray, 100%). Dotted lines are similar, you must specify the number of dots. ``` line x1 y1 x2 y2 [size] [color] [opacity] ```  ``` dline x1 y1 x2 y2 [size] [gap] [color] [opacity] ```  ``` hline x y length [size] [color] [opacity] ```  ``` vline x y length [size] [color] [opacity] ```  A "pill" shape has is a horizontal line with rounded ends. ``` pill x w length size [color] ```  Curve is a quadratic Bezier curve: specify the beginning location `(bx, by)`, the control point `(cx, cy)`, and ending location `(ex, ey)`. For arcs, specify the location of the center point `(x,y)`, the width and height, and the beginning and ending angles (in degrees). Line thickness, color and opacity are optional, with defaults (0.2, gray, 100%). ``` curve bx by cx cy ex ey [size] [color] [opacity] ```  ``` arc x y w h a1 a2 [size] [color] [opacity] ```  To make n-sided stars, use the "star" keyword: `(x,y)` is the center of the star, `np` is the number of points, and `inner` and `outer` are the sizes of the inner and outer points, respectively. ``` star x y np inner outer [color] [opacity] ```  ## Arrows Arrows with optional linewidth, width, height, color, and opacity. Default linewidth is 0.2, default arrow width and height is 3, default color and opacity is gray, 100%. The curve variants use the same syntax for specifying curves. ``` arrow x1 y1 x2 y2 [linewidth] [arrowidth] [arrowheight] [color] [opacity] ```  ``` lcarrow bx by cx cy ex ey [linewidth] [arrowidth] [arrowheight] [color] [opacity] ```  ``` rcarrow bx by cx cy ex ey [linewidth] [arrowidth] [arrowheight] [color] [opacity] ```  ``` ucarrow bx by cx cy ex ey [linewidth] [arrowidth] [arrowheight] [color] [opacity] ```  ``` dcarrow bx by cx cy ex ey [linewidth] [arrowidth] [arrowheight] [color] [opacity] ```  ## Braces Left, right, up and down-facing braces. (x, y) is the location of the point of the brace, (aw, ah) are width and height of the braces's end curves; `linewidth`, `color` and `opacity` are optional (defaults are 0.2, gray, 100%) ``` lbrace x y height aw ah [linewidth] [color] [opacity] ```  ``` rbrace x y height aw ah [linewidth] [color] [opacity] ```  ``` ubrace x y width aw ah [linewidth] [color] [opacity] ```  ``` dbrace x y width aw ah [linewidth] [color] [opacity] ```  ## Brackets Left, right, up and down-facing brackets. (x, y) is the location of the center of the bracket. For left and right-facing brackets, `width` is the size of the top and bottom portions, and `height` is the span of the bracket. For upward and downward-facing brackets, `width` is the span of of bracket, and `height` is the size of the left and right portions. `linewidth`, `color` and `opacity` are optional (defaults are 0.2, gray, 100%) ``` lbracket x y width height [linewidth] [color] [opacity] ```  ``` rbracket x y width height [linewidth] [color] [opacity] ```  ``` ubracket x y width height [linewidth] [color] [opacity] ```  ``` dbracket x y width height [linewidth] [color] [opacity] ```  ## Charts Run the [dchart](https://github.com/ajstarks/dchart/blob/master/README.md "dchart") command with the specified arguments. ``` dchart [args] ``` For example, ```dchart -bar=t -left=35 -right=65 -top=90 -bottom=65 -yaxis=t```  Alternatively, some chart types may be drawn using their own dedicated keywords, optionally specifying chart, label, and value colors: ## Barchart ```barchart "file" [color] [lcolor] [vcolor]```  ## Scatter chart ```scatterchart "file" [color] [lcolor] [vcolor]```  ## Line Chart ```linechart "file" [color] [lcolor] [vcolor]```  ## Area chart ```areachart "file" [color] [lcolor] [vcolor]```  ## Dotchart ```dotchart "file" [color] [lcolor] [vcolor]```  ## Horizontal bar chart ```hbarchart "file" [color] [lcolor] [vcolor]```  ## "Word" barchart ```wbarchart "file" [color] [lcolor] [vcolor]```  ## Slope chart ```slopechart "file" [color] [lcolor] [vcolor]```  ## Proportional map ```pmap "file" [size]```  ## Pie chart ```pie "file" [size]```  ## Donut chart: ```donut "file" [size] [width]```  ## Proportional grid ```pgrid "file"```  ## Waffle chart ```waffle "file"```  ## Fan chart ```fanchart "file" [size]```  ## Bwotie chart ```fanchart "file" [size]```  When using chart keywords, special variables may be used to control chart attributes: ``` Description variable Default Value Chart top chartTop 80 Chart bottom chartBottom 30 Chart left chartLeft 10 Chart right chartRight 90 Chart text size chartTextSize 1.5 Chart line width chartLineWidth 0.2 Chart bar width chartBarWidth 0 (autoscale) Chart line spacing chartLineSpacing 2.4 Chart Volume opacity chartVolOp 50 X-axis label interval chartXLabel 1 (1: all, 0: none, every nth labelchartYRange Y-axis range chartYRange "" (min,max,interval) CSV Columns chartCSVCols "" Data Format chartDataFmt "%.1f" Show % value chartPercent 0 (0: off, 1: on) Show values chartVal 1 (0: off, 1: on) Show y-axis grid chartGrid 0 (0: off, 1: on) Show title chartTitle 1 (0: off, 1: on) Read CSV chartReadCSV 0 (0: off, 1: on) Show last X-axis label chartXLast 0 (0: off, 1: on) ``` The chart boundaries may be set via ```chartbbox```. ```chartbbox left [right] [top] [bottom]``` For example: ``` chartLeft=50 chartRight=90 chartTop=30 chartBottom=10 chartXLabel=2 linechart "AAPL.d" "red" ``` makes:  ## Legend Show a colored legend ``` legend "text" x y size [font] [color] ```  # Geographic Features  Using data from either: * [Shapefiles](https://desktop.arcgis.com/en/arcmap/latest/manage-data/shapefiles/what-is-a-shapefile.htm) * [KML files](https://pro.arcgis.com/en/pro-app/latest/help/data/kml/what-is-kml-.htm) * [geoJSON files](https://datatracker.ietf.org/doc/html/rfc7946) * sets of lat/long pairs geographic features may be rendered. Supported are: * geographic regions, borders and paths * plain and labeled locations * images at geographic locations Appropriate geoJSON, KML and Shapefiles may be obtained from the [opendatasoft site](https://public.opendatasoft.com/explore/dataset/world-administrative-boundaries/export/) The map above is rendered by this code: ``` deck wcolor="lightblue" lcolor="sienna" gcolor="white" geoLatMin=20 geoLatMax=45 geoLongMax=48 geoLongMin=5 slide wcolor gcolor text "The Ancient World" 10 10 5 georegion "world.kml" lcolor geoborder "world.kml" 0.05 wcolor geolabel "countries.d" 3 "serif" gcolor geoloc "cities.d" "c" 1 "sans" gcolor eslide edeck ``` (Note: to ensure proper layout, set the -layers option to "poly:ellipse:text:line" in your deck rendering tool.) The geographic bounding box of the map is defined by latitude (geoLatMin, geoLatMax) and longitude (geoLongMin, geoLongMax) in decimal degrees. Latitudes range from -90° to 90° and longitudes range from -180° to 180°. The Equator is at 0° latitude; latitudes to the north of the Equator are positive, and latitudes south of the Equator are negative. The Prime Meridian is 0° longitude; longitudes to the east of this point are positive, longitudes to the west are negative. Once the ```geoLatMin, geoLatMax, geoLongMin, geoLongMax``` variables are set, geographic functions will use them implicitly. If these special variables are not set, the default values (-90,90,-180,180) are used.  Further, the canvas boundaries for geographic functions are: ```geoXmin, geoXmax``` for the width and ```geoYmin, geoYmax``` for the height. If these special variables are not set the default values (0,100) are used. For example to show the African continent (bound by 37.347N to 34.8333S and 17.52W to 51.267E) on a specified portion of the canvas (40,70) and (30,70): ``` geoLatMax=37.346983 geoLatMin=0-34.833222 geoLongMax=51.266667 geoLongMin=0-17.520278 geoXmin=40 geoYmax=70 geoYmin=30 geoXmax=70 ```  ## Geographic and Canvas bounding boxes Set the lat/long boundaries for subsequent geographic operations (```geobbox``` is an alternative keyword) ``` geobound latmin [latmax] [longmin] [longmax] ``` bounding boxes may also be specified using geo: URLs: ``` geobound "geo:-34.833222,-17.520278" "geo:37.346983,51.266667" ``` ``` af1="geo:-34.833222,-17.520278" af2="geo:37.346983,51.266667" geobound af1 af2 ``` Set the canvas bounds for geographic operations ``` geocanvas xmin [xmax] [ymin] [ymax] ``` Access the canvas coordinates that correspond to a geographic location with the ```geocoord``` assignment: ``` v=geocoord "geo:40.621255,-74.439466" ``` or ``` v=geocoord 40.621255 -74.439466 ``` The (x,y) coordinates are accessed: ``` circle v_x v_y 1 "red" ``` ## Regions  Reads data from the specified KML, geoJSON or Shapefile and renders the regions. A file with the suffix ".kml" is assumed to be in KML format. Files with suffix ".json" or "geojson" are processed as geoJSON, and a file with the ".shp" suffix is assumed to be a Shapefile. ```color``` and ```op``` specify the color and opacity. ``` georegion "file" [color] [op] ``` ## Borders  Reads data from the specified file and renders the borders. ```lw``` is the line width, ```color``` and ```op``` specify the color and opacity. ``` geoborder "file" [lw] [color] [op] ``` ## Labels  Reading from the specified file, or a geo coordinate string, place text at a latitude and longitude. The fields in the file are tab-separated latitude, longitide, and label. Labels with embedded "\n" means the text will be stacked. (for example "Atlantic\nOcean"). A file of coordinates looks like this: ``` 26.3351 17.2283 Libya 26.8206 30.8025 Egypt 39.0742 21.8243 Greece 38.9637 35.2433 Turkey 41.8719 12.5674 Italy 32.4279 53.6880 Iran 33.2232 43.6793 Iraq 34.0000 09.0000 Tunisia ``` Coordinate strings may be either a string with tab separated values: ``` "+26.3351 17.2283 Libya" ``` or [geo URI](https://en.wikipedia.org/wiki/Geo_URI_scheme) like this: ``` geo:26.3351,17.2283 ``` ``` geolabel "file.d" [size] [font] [color] [op] geolabel "+41.8719 12.5674 Italy" [size] [font] [color] [op] geolabel "geo:41.8719,12.5674 Italy" [size] [font] [color] [op] ``` ## Locations  Reading data from the specified file or coordinate string, place text and a dot. The text may be center-above ("c"), center-underneath ("u"), begin ("b"), or end ("e") aligned in relation to the dot. ``` geoloc "location" align [size] [font] [color] [op] ``` Place a marker at the locations specified in the specified file or coordinate string.  ``` geomark "location" [size] [color] ``` Connect the points found in the specified file with straight lines. ``` geopathfile "file" [size] [color] ``` Connect two points with either straight lines or curves   ``` geopath "point1" "point2" [size] [color] [op] geoarc "point1" "point2" [size] [color] [op] ```` ## Images on maps  ``` geoimage "loc" image-width image-height ``` Place image(s) at location(s) The location is specified by lat/long and name of the image. The ```loc``` argument may be either a geo URL and a name, or a list of coordinates and names in a file. For example: ``` geoimage "geo:48.8588897,2.3200410 fra.png" 10 0 ``` places the image in "fra.png" at the coordinates of Paris, France.