flexinterpn_method
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— | flexinterpn_method [2010/06/21 05:23] (current) – created jochen | ||
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+ | ====== flexinterpn_method ====== | ||
+ | This is a proxy function for [[flexinterpn]]. It only handles some standard kernels as well as 2D to 3D data conversion for rotation. | ||
+ | |||
+ | ===== Motivation ===== | ||
+ | While the [[flexinterpn]] function allows very flexible interpolation of data, it would be too cumbersome to expect that every user (including myself) will create a suitable kernel window over and over again whenever data is to be interpolated. | ||
+ | |||
+ | The flexinterpn_method function creates a persistent variable and stores some of the more standard kernel windows in a 4096-sampling resolution (enough to allow the linear interpolation internally applied by [[flexinterpn]] to yield high-quality results, tested with the Lanczos8 window mentioned at the [[http:// | ||
+ | |||
+ | ===== Function reference ('help flexinterpn_method' | ||
+ | < | ||
+ | |||
+ | FORMAT: | ||
+ | |||
+ | Input fields: | ||
+ | |||
+ | data N-d data (up to 4 dims supported) | ||
+ | cr CxD coordinates or 4xD range | ||
+ | opts hold (and tranformation matrix) | ||
+ | method | ||
+ | ' | ||
+ | ' | ||
+ | |||
+ | Output fields: | ||
+ | |||
+ | idata | ||
+ | k | ||
+ | |||
+ | Note: the range notation of cr must contain Infs in the first row | ||
+ | of values, the rest is parsed as row2: | ||
+ | |||
+ | Note: for methods other than nearest and linear, the value range of | ||
+ | the input can be exceeded!</ | ||
+ | |||
+ | ===== Arguments ===== | ||
+ | The first two arguments, '' | ||
+ | |||
+ | ==== opts ==== | ||
+ | Here, neither, the first, or both of the last two arguments of [[flexinterpn]] can be given (so, possibly, neither '' | ||
+ | |||
+ | ==== method ==== | ||
+ | The following methods (kernel shapes) are supported: | ||
+ | * cubic (hermite cubic spline, see bottom of the [[http:// | ||
+ | * lanczos2/3 (same information source) | ||
+ | * linear (standard kernel, '' | ||
+ | * nearest (this is only an approximation! for very few interpolation coordinate, the value will yet be a linear interpolation, | ||
+ | * poly3/ | ||
+ | |||
+ | ===== Usage ===== | ||
+ | There are two main uses of this function: | ||
+ | |||
+ | * actual data interpolation (passing on data to [[flexinterpn]]): | ||
+ | resampled = flexinterpn_method(data, | ||
+ | * generating/ | ||
+ | [null, k] = flexinterpn_method(1, | ||
flexinterpn_method.txt · Last modified: 2010/06/21 05:23 by jochen