HOP

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NAME

hop - calculate and display a doily pattern

SYNOPSIS

hop [-AFHLRSZmu][-w width][-h height][-o filename][-C colorwheel][-D numdemos][-E exponent][-abcde value][-l limit][-p period][-s scale]

DESCRIPTION

hop generates and graphically displays a doily-like pattern by iterating one of several parametric maps of the plane. Maps include use of the square root, sine, logarithmic, and linear functions.

OPTIONS

-R: Indicates the display will be in the root window. In this mode, the default color map will be used and no spinning of the color wheel is possible.
-C n: Selects one of many different color wheels to use. The default color wheel is a rainbow palette.
-D n: Indicates demo mode. In this mode, the doily will be calculated, displayed, and spun. The numeric argument indicates the number of successive runs (each using different parameters and maps). The program exits after the last run.
-w n: Specifies the width of the window. Default is full screen.
-h n: Specifies the height of the window. Default is full screen.
-o filename: Specifies the output filename to be used. If the -o option is given, this file will automatically be written out at the completion of the drawing. If it is not specified, a default filename of hop.ppm is used and only written if the 'f' or 'F' keys are pressed during a run. The format of the output file is PPM. The parameters used to calculate the picture are included as comments at the beginning of the output file.
-u: Produces a usage message.

NOTES

During display, use of the keys +-aAbBCfFnNrswWX?hqQ indicates:

           (+) Increment minimum color index.
           (+) Decrement minimum color index.
           (a or A) Use the log function with new parameters
           (b or B) Toggle use of a maximum number of points limit
           (c or C) Clear the window and re-initialize the points
           (d or D) Decrease or increase the delay in color wheel spinning
           (f or F) Save the window contents to a PPM format file
           (H) Toggle histogram computation and display
           (j or J) Randomly select which function to use (with new parameters)
           (k or K) Use the square root function with new parameters
           (l or L) Use the linear function with new parameters
           (m or M) Use the sine function with new parameters
           (n or N) Skip to the next doily (same function or different function).
           (r or R) Decrement or increment the histogram algorithm index
           (s) Spin the color wheel (toggling direction)
           (S) Stop spinning the color wheel
           (W or w) Increment or decrement the color map index.
           (X) Erase the existing pattern and restart the computation and display
           (Q or q) quit

AUTHOR

        Ronald Joe Record
     The Santa Cruz Operation 
          P.O. Box 1900
       Santa Cruz, CA 95061
            rr@sco.com

ACKNOWLEDGEMENTS

The original algorithm (square root only) was published in the September 1986 Scientific American. Assistance with colormaps and spinning color wheels and X was gleaned from Hiram Clawson and Stacey Campbell.

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Time: 04:06:18 GMT, December 02, 2024