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diff --git a/doc/user/gra_over b/doc/user/gra_over new file mode 100644 index 0000000..1b9653a --- /dev/null +++ b/doc/user/gra_over @@ -0,0 +1,179 @@ +@Section + @Title { Changing the overall appearance of the graph } + @Tag { overall } +@Begin +@PP +The overall appearance of the graph is controlled by options to the +@Code "@Graph" symbol. As usual, these options follow the @Code "@Graph" +symbol, with their values enclosed in braces; they may appear in any order, +and if omitted are assigned some sensible default value. +@PP +There is a @Code "style" option for controlling the overall style of the +style.graph @Index { @Code "style" option of @Code "@Graph" } +axes. @Index { axes in graphs } +graph, whose value may be either {@Code "frame"}, {@Code "none"}, +or {@Code "axes"}. The default value is {@Code "frame"}, and it produces +a frame around the graph with ticks and labels along its left and bottom +edges, as in previous examples. The {@Code "none"} style prints +nothing (no frame, no ticks, no labels), which is useful for producing +graphs that don't look like graphs, as it were. +@PP +If the other value, {@Code "axes"}, is chosen, two other options called +{@Code xorigin} and {@Code yorigin} become compulsory: +@ID @OneRow @Code { +"-2p @Font @Graph" +" style { axes }" +" xorigin { 0 }" +" yorigin { 0 }" +" width { 12 cm }" +" height { 7 cm }" +" leftcaption { 90d @Rotate { counts (%) } }" +" leftgap { 1.0 cm }" +" belowcaption { time (min) }" +" belowgap { 0 cm }" +"{" +" @Data" +" points { filledsquare }" +" pairs { solid }" +" { 0 0.0 1 4.8 2 7.0 3 15.2 4 19.8 5 20.0 6 21.0 7 25.0" +" 10 29.5 15 31.2 20 35.0 30 40.0 60 50.8" +" }" +"" +" @Data" +" points { square }" +" pairs { solid }" +" {" +" 0 0.0 1 3.7 1.5 43.1 2 99.1 3 85.6 4 69.1 5 47.0 6 44.1 7 40.8" +" 10 35.0 15 29.4 20 25.0 30 21.1 60 15.5" +" }" +"}" +} +We have requested a smaller font size for this graph as a whole by +preceding it with {@Code "-2p @Font"}, meaning two points smaller, and +we have used some other options which will be explained shortly. The +resulting graph has an x axis and a y axis instead of a frame, like this: +@CD -2p @Font @Graph + style { axes } + xorigin { 0 } + yorigin { 0 } + width { 12 cm } + height { 7 cm } + leftcaption { 90d @Rotate { counts (%) } } + leftgap { 1.0 cm } + belowcaption { time (min) } + belowgap { 0 cm } +{ + @Data + points { filledsquare } + pairs { solid } + { 0 0.0 1 9.5 2 15.0 3 18.2 4 20.1 5 22.1 7 25.0 + 10 28.3 15 31.2 20 35.0 30 40.0 60 50.8 + } + + @Data + points { square } + pairs { solid } + { + 0 0.0 1 3.7 1.5 43.1 2 99.1 3 85.6 4 69.1 5 47.0 6 44.1 7 40.8 + 10 35.0 15 29.4 20 25.0 30 21.1 60 15.5 + } +} +The point where the axes cross is ({@Code xorigin}, {@Code yorigin}). +@PP +Although @Code "@Graph" does not provide explicit support for +multiple axes, you can simulate them by overstriking two +separate graphs of equal size. There is an @Code "@OverStrike" +overstrike. @Index @Code "@OverStrike" +symbol which overstrikes two objects, so +@ID @Code "@Graph { ... } @OverStrike @Graph { ... }" +will do the job. Typically one of the graphs would have y ticks, +and the other would have r ticks (adjacent to the right-hand side of the +frame). +@PP +There are @Code "xlog" and @Code "ylog" options which produce +logarithmic.axes @Index { logarithmic axes in graphs } +logarithmic x and y axes: +@ID @OneRow @Code { +"@Graph" +" xlog { 10 }" +" ylog { 10 }" +"{" +" ..." +"}" +} +The value is the base of the logarithm, usually 10 or 2, or +{@Code none} (the default) meaning not logarithmic. Logarithms +to different bases differ only by a constant factor, so the main effect +of different bases is on the choice of ticks and labels. An @Code "xlog" +option will be ignored if there are any negative or zero x data points, +x ticks, or {@Code "xorigin"} or {@Code "xmin"} options; and similarly +for {@Code "ylog"}. +@PP +There are @Code "width" and @Code "height" options for setting the size +of the total area enclosed: +@ID @OneRow @Code { +"@Graph" +" width { 6.0 cm }" +" height { 4.0 cm }" +"{" +" ..." +"}" +} +This shows the default width and height, six centimetres and four +centimetres. These lengths and others discussed below can be specified +using a variety of units of measurement (see Section {@NumberOf grsummary} +for the details). +@PP +Within the frame or axes, a small margin is kept free of data points. The +size of this margin is controlled by @Code "xextra" and @Code "yextra" +options: +@ID @OneRow @Code { +"@Graph" +" xextra { 0.5 cm }" +" yextra { 0.5 cm }" +"{" +" ..." +"}" +} +Setting @Code "xextra" to @Code "0.5 cm" (the default value if the +@Code style option is {@Code frame}) means that the smallest x value +will be placed 0.5 centimetres to the right of the left boundary, and +the largest will be placed 0.5 centimetres to the left of the right +boundary. It is quite safe to set @Code "xextra" to @Code "0 cm" if +desired, and indeed this is the default value when @Code style is +{@Code axes} or {@Code none}. The @Code "yextra" option works in +exactly the same way for y values. +@PP +The @Code "xdecreasing" option plots the x values in decreasing order +instead of increasing: +@ID @Code { +"@Graph" +" xdecreasing { yes }" +" abovecaption { New South Wales road deaths, 1960--1990" +"(fatalities per 100 million vehicle km) }" +"{" +" @Data" +" points { plus }" +" pairs { dashed }" +" {" +" 1963 5.6 1971 4.3 1976 3.7 1979 3.4 1982 2.9 1985 2.3 1988 2.0" +" }" +"}" +} +produces +@CD @Graph + xdecreasing { yes } + abovecaption { New South Wales road deaths, 1960--1990 +(fatalities per 100 million vehicle km) } +{ + @Data + points { plus } + pairs { dashed } + { + 1963 5.6 1971 4.3 1976 3.7 1979 3.4 1982 2.9 1985 2.3 1988 2.0 + } +} +The value of @Code "xdecreasing" should be either @Code "no" (the default +value) or {@Code "yes"}. A similar @Code "ydecreasing" option does the same +thing to the y axis. +@End @Section |