tv (LUX)

15.5.653 tv

tv, image [, x=x, y=y, window=window, scale=scale] [, /dev, /dvi, /img, /plt, /rim, /rpl] [, /pdev, /screen, /postscript, /plotwindow, /zoom, /center, /bit24]

[x11] Displays an image.

Parameters:

image: The image to display. It must be a two-dimensional non-complex numerical array, except if /bit24 is specified (see below). If image is a byte array, then it is taken to contain indices into the color map and tv acts like tvmap. Otherwise, the image values are scaled for maximum image contrast.
x, y: The coordinates at which the image is to be displayed. They must be scalars. The coordinate system is determined by some of the keywords (see below). If these parameters are not specified, then the image is displayed at coordinates !tvix, !tviy.
window: The window or pixmap in which the image is to be displayed. It must be a scalar, between -#max_pixmap and #max_window (inclusive). If this parameter is not specified, then the value from !window is used.
scale: The scale at which the image is to be displayed. This must be a nonnegative scalar. A value of 0 (or /noscale) yields the images’s natural size (with one array element corresponding to one pixel). A value of 1 (or /scale) yields the greatest integer scale value that still allows display of the whole image within the window. Any other value (either smaller or greater than 1) yields an image that is scaled by that factor relative to its natural dimensions. If scale is greater than 1, then interpolation is used in generating the expanded view. The type of interpolation is governed by !tvsmt. If this argument is not specified, then the value from !tvscale is used. If /zoom or /plotwindow are specified, then this argument is ignored.

Keywords:

/dev, /dvi, /img, /plt, /rim, /rpl: These keywords specify the coordinate system in which the position of the image is interpreted. The default is the device-dependent (dev) system.
/pdev, /screen, /postscript: These keywords specify where the image is sent. /screen selects display on the screen, /postscript selects sending to the PostScript file indicated by !ps_file, and /pdev selects the target based on the value of !pdev. By default, /screen is assumed.
/plotwindow: If this keyword is selected, then the image fills the current plot window (governed by !wxb, !wxt, !wyb, !wyt).
/zoom: If this keyword is selected, then that part of the image is displayed that corresponds to the last use of zoom (governed by !zoomx, !zoomy, !zoommag).
/center: If this keyword is selected, then the x and y coordinates refer to the center of the image rather than its lower left-had corner.
/bit24: If this keyword is selected, then image must be a three-dimensional non-complex array with 3 elements in the third dimension. Then the third dimension selects the red, green, and blue components for each pixel in the image. This keyword is only useful if a 24-bit visual is used (xopen).

Affected system variables:

!tvix: The dev x coordinate of the left edge of the image.
!tvixb: The dev x coordinate of the right edge of the image.
!tviy: The dev y coordinate of the bottom edge of the image.
!tviyb: The dev y coordinate of the top edge of the image.
!tvscale: The used magnification scale, if any. This variable is unaffected if /plotwindow is set.

For backward compatibility with older versions of LUX, if set,/ulimcoords has been executed beforehand, then the position (x,y) is counted from the upper left-hand corner instead, and images are shown with their y coordinate increasing downward rather than upward.

Alias: xtv