util/

vis_linear_function.pro

graphics computation

Create a function which maps in_range to out_range with a linear function.

To create a linear function that maps the x-range of a surface object to the range -0.75 to 0.75 use:

  osurface->getProperty, xrange=xr
  xc = vis_linear_function(xr, [-0.75, 0.75])
  osurface->setProperty, xcoord_conv=xc

This provides a more flexible method of creating linear functions than the typical:

  osurface->getProperty, xrange=xr
  xc = norm_coord(xr)
  xr[0] -= 0.5
  osurface->setProperty, xcoord_conv

which can only "normalize" the dimension i.e. make its size equal to 1 (not an aribitrary size like the VIS_LINEAR_FUNCTION example).

result = vis_linear_function(in_range, out_range [, data=fltarr])

Create a function which maps in_range to out_range with a linear function.

2-element array of type of in_range and out_range; or scaled data if DATA keyword is present

in_range in required type=2-element numeric array

input range

out_range in required type=2-element numeric array

output range