plotSetXRange¶

Purpose¶

Sets the range for the x-axis.

Format¶

plotSetXRange(&myPlot, x_min, x_max)¶

Parameters

&myPlot (struct pointer) – A plotControl structure pointer.
x_min (Scalar, or 2x1 matrix) – minimum limit of the x-axis.
x_max (Scalar, or 2x1 matrix) – maximum limit of the x-axis.

Examples¶

Basic usage¶

// Declare plotControl structure
struct plotControl myPlot;

// Initialize plotControl structure
myPlot = plotGetDefaults("scatter");

// Set x-axis to to range from -5 to +5
plotSetXRange(&myPlot, -5, 5);

// Create and plot data using our x-range
x = rndn(100, 1);
y = rndn(100, 1);

plotScatter(myPlot, x, y);

Set separate ranges for the top and bottom x-axes¶

We will create the plot shown above, comparing S&P 500 earnings data from two decades by plotting one of the series against the bottom x-axis and the other against the top x-axis. The call to plotSetWhichXAxis() below specifies that the first column plotted will be assigned to the bottom x-axis, while the second column plotted will be plotted against the top x-axis.

// Declare plotControl structure
// and apply default settings
struct plotControl myPlot;
myPlot = plotGetDefaults("xy");

// S&P500 earnings data
y60s = { 1960, 1962, 1964, 1966, 1968, 1970 };
y70s = { 1971, 1972, 1973, 1974, 1975, 1976 };

earn60s = { 3.1, 3.67, 4.76, 5.41, 5.72, 5.51 };
earn70s = { 5.57, 6.17, 7.96, 9.35, 7.71, 9.75 };

// Set the range for the bottom x-axis from 1960 to 1970
// and set the range for the top x-axis from 1970 to 1980
x_min = { 1960, 1970 };
x_max = { 1970, 1980 };
plotSetXRange(&myPlot, x_min, x_max);

// Assign the 1st column (which will be the 1960's data) to the bottom x-axis.
// Assign the 2nd column (1970's data) to the top x-axis
plotSetWhichXAxis(&myPlot, "bottom" $| "top");

plotSetLegend(&myPlot, "1960's"$|"1970's");

plotSetYRange(&myPlot, 0, 10);
plotSetYLabel(&myPlot, "USD / Share");

// Draw plot with 60's data as the first column and
// the 70's data second to be consistent with the
// above call to plotSetWhichXAxis
plotXY(myPlot, y60s~y70s, earn60s~earn70s);

Remarks¶

If x_min or x_max are scalar values, they will apply to the top and bottom x-axis. If they are 2x1 matrices, the first element will control the bottom x-axis and the second will control the top x-axis.

This function sets an attribute in a plotControl structure. It does not affect an existing graph, or a new graph drawn using the default settings that are accessible from the Tools > Preferences > Graphics menu.