Functions

Summary

Create a basic-graph-spec object.

Package

lw-gt

Signatures

make-basic-graph-spec function start-x step-x range &key color thickness name x-offset y-offset x-scale y-scale var1 var2 var3 var4 var5 var6 => basic-graph-spec

basic-graph-spec-p object

copy-basic-graph-spec graph-spec

generate-graph-from-graph-spec graph-spec

Arguments

function

A function of two arguments x and y.

start-x

step-x

range

color

thickness

name

x-offset

y-offset

x-scale

y-scale

var1

var2

var3

var4

var5

var6

Values

basic-graph-spec

A basic-graph-spec object.

Description

The function make-basic-graph-spec creates a basic-graph-spec object. This object can be modified by the basic-graph-spec-* accessors. The function generate-graph-from-graph-spec generates the graph using the current values in the basic-graph-spec object, which is a drawing-object which when drawn draws the graph, which means drawing a line between each two successive points.

function must be a function of two arguments: the basic-graph-spec and the x value. It needs to return the corresponding y value.

start-x , step-x and range define which x values to use: the first value is start-x , and then increase by step-x until the x is greater than (+ start-x range ). For each x value, generate-graph-from-graph-spec calls function with the graph-spec and the x value to generate the y value.

x-scale and y-scale (default to 1) are used to scale the x and y after calling function , by multiplying the x and y by x-scale and y-scale respectively.

x-offset and y-offset (default to 0) are used to translate the scaled values of x and y by adding the x-offset and y-offset to the scaled x and y.

The scaled and transformed pair x, y define a point. generate-graph-from-graph-spec then generates a drawing-object that draws a line between each two successive points.

thickness and color specify the thickness and the color of the lines. The lines are drawn with scale-thickness nil.

name and all the var n values are arbitrary values, which you can use to store anything that the function needs to compute the y value. The system does not read or write them.

The function copy-basic-graph-spec can be used to copy a basic-graph-spec. basic-graph-spec-p is the predicate.

See also

basic-graph-spec
generate-graph-from-pairs
drawing-object
Higher level - drawing graphs and bar charts