functions in random_et.i -
kolmogorov
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kolmogorov(diam, r0, all=, orig=, seed=) kolmogorov(diam, all=, orig=, seed=) returns an array of random phases which follow Kolmogorov law on a square pupil of DIAM pixels per side with a Fried's parameter equal to R0 (in pixels, default is to set R0=DIAM). If a Point Spread Function is to be calculated from the generated phase screen, it should be conveniently sampled (i.e., R0 greater or equal 2 or 3 pixels). The algorithm is the mid-point method of R.G. Lane, A. Glindemann and J.C. Dainty (``Simulation of a Kolmogorov phase screen'' in Waves in Random Media, 2, 209-224, 1992). Keyword ORIG is a flag which indicates whether or not the original method by Lane et al. should be used (default is to use the original algorithm). Keyword ALL is a flag which indicates whether or not all the computed phase screen should be returned. The default behaviour is to return the smallest array into which a pupil with diameter DIAM can fit. The computed phase screen is a (2^N+1)*(2^N+1) array. Keyword SEED is a scalar between 0.0 and 1.0 non-inclusive and is used to reinitialized the random sequence. If SEED is out of range, the sequence is reinitialized as when Yorick starts. | |
SEE ALSO: | random_normal |
random_normal
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random_normal(dimemsion_list) returns an array of normally distributed random double values with the given DIMENSION_LIST (nil for a scalar result). Keyword SEED is a scalar between 0.0 and 1.0 non-inclusive and is used to reinitialized the random sequence. If SEED is out of range, the sequence is reinitialized as when Yorick starts. The algorithm follows the Box-Muller method (see Numerical Recipes by Press et al.). | |
SEE ALSO: | random, random_poisson, random_normal_prev |
random_normal_prev
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random_normal_prev= [] if not nil, is the previous value computed by random_normal. |
random_poisson
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random_poisson(mean) returns an array of random double values which follow a Poisson law of parameter MEAN (the output has the same geometry of the input). Keyword SEED is a scalar between 0.0 and 1.0 non-inclusive and is used to reinitialized the random sequence. If SEED is out of range, the sequence is reinitialized as when Yorick starts. The code is adapted from `POIDEV' an IDL routine by Wayne Landsman and the algorithm is from Numerical Recipes by Press et al. | |
SEE ALSO: | random, random_normal |
random_uniform
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random_uniform(dimemsion_list, seed=) returns an array of uniformly distributed random double values with the given DIMENSION_LIST (nil for a scalar result). Keyword SEED is a scalar between 0.0 and 1.0 non-inclusive and is used to reinitialized the random sequence. If SEED is out of range, the sequence is reinitialized as when Yorick starts. | |
SEE ALSO: | random, random_poisson, random_normal_prev |