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+ + +Calculate the background of a waveform or image. Errors if scalar provided.
+Waveform: +First, applies smoothing by taking weighted nearest and next-nearest +neighbour contributions to y values whose difference from their neighbours +is more than 0.2 times the total range in y. +The first 25 and last 25 y values in the signal are averaged to give an +estimate of the background.
+Image: +The average pixel value in the 10 by 10 region in the top left of the image +is returned.
+ +builtins/background.py27 +28 +29 +30 +31 +32 +33 +34 +35 +36 +37 +38 +39 +40 +41 +42 +43 +44 +45 +46 +47 +48 +49 +50 +51 +52 +53 | |
Calculate the centre of a waveform. Errors if image or scalar provided.
+First, applies smoothing by taking weighted nearest and next-nearest +neighbour contributions to y values whose difference from their neighbours +is more than 0.2 times the total range in y.
+The global maximum y value is then identified along with the first x positions +either side of the peak where the y value is less than or equal to half the +global maximum. If all values of y to one side of the peak are greater than +half the global maximum, the position of the global maximum is used. The value +of x at these two positions is averaged and returned.
+Note this will not be the same as the x value of the maximum, unless the data +is symmetric.
+ +builtins/centre.py29 +30 +31 +32 +33 +34 +35 +36 +37 +38 +39 +40 +41 +42 +43 +44 +45 +46 +47 +48 | |
Calculate the x position of the centroid of an image. Errors if waveform or +scalar provided.
+Returns the x position of the image's centroid in terms of pixels.
+ +builtins/centroid_x.py20 +21 +22 +23 +24 +25 +26 +27 +28 | |
Calculate the y position of the centroid of an image. Errors if waveform or +scalar provided.
+Returns the y position of the image's centroid in terms of pixels.
+ +builtins/centroid_y.py20 +21 +22 +23 +24 +25 +26 +27 +28 | |
Calculate the falling edge of a waveform. Errors if image or scalar provided.
+First, applies smoothing by taking weighted nearest and next-nearest +neighbour contributions to y values whose difference from their neighbours +is more than 0.2 times the total range in y. The global maximum y value is then +identified along with the first x position to the right of the peak where the y +value is less than or equal to half the global maximum. If all values of y to +the right of the peak are greater than half the global maximum, the position of +the global maximum is used. The value of x at this position is returned."
+ +builtins/falling.py25 +26 +27 +28 +29 +30 +31 +32 +33 +34 +35 +36 +37 +38 +39 | |
Calculate the FWHM of a waveform. Errors if image or scalar provided.
+First, applies smoothing by taking weighted nearest and next-nearest +neighbour contributions to y values whose difference from their neighbours +is more than 0.2 times the total range in y.
+The global maximum y value is then identified along with the first +positions to either side of the peak where the y value is less than or +equal to half the global maximum. If all y values to one side of the peak +are greater than half the global maximum, the position of the global +maximum is used. The difference between the values of x at these two +positions is returned.
+ +builtins/fwhm.py27 +28 +29 +30 +31 +32 +33 +34 +35 +36 +37 +38 +39 +40 +41 +42 +43 +44 | |
Calculate the FWHM of an image across the x axis, at the y position of the image +centroid. Errors if waveform or scalar provided.
+First, calculates the centroid and extracts the row at that position. Then +applies smoothing by taking weighted nearest and next-nearest neighbour +contributions to pixel values whose difference from their neighbours is more +than 0.2 times the total range in values.
+The global maximum value is then identified along with the first +positions to either side of the peak where the pixel value is less than +or equal to half the global maximum. If all pixel values to one side of +the peak are greater than half the global maximum, the position of the +global maximum is used. The difference between these two positions in +number of pixels is returned.
+ +builtins/fwhm_x.py33 +34 +35 +36 +37 +38 +39 +40 +41 +42 +43 +44 +45 +46 +47 +48 +49 +50 +51 +52 +53 +54 +55 +56 | |
Calculate the FWHM of an image across the y axis, at the x position of the image +centroid. Errors if waveform or scalar provided.
+First, calculates the centroid and extracts the column at that position. Then +applies smoothing by taking weighted nearest and next-nearest neighbour +contributions to pixel values whose difference from their neighbours is more +than 0.2 times the total range in values.
+The global maximum value is then identified along with the first +positions to either side of the peak where the pixel value is less than +or equal to half the global maximum. If all pixel values to one side of +the peak are greater than half the global maximum, the position of the +global maximum is used. The difference between these two positions in +number of pixels is returned.
+ +builtins/fwhm_y.py33 +34 +35 +36 +37 +38 +39 +40 +41 +42 +43 +44 +45 +46 +47 +48 +49 +50 +51 +52 +53 +54 +55 +56 | |
Integrate a waveform or image. Errors if scalar provided.
+Waveform: +First, applies smoothing by taking weighted nearest and next-nearest +neighbour contributions to y values whose difference from their neighbours +is more than 0.2 times the total range in y. +The y values are then integrated with respect to x, with the last y value +neglected.
+Image: +Return the sum of all pixel values.
+ +builtins/integrate.py25 +26 +27 +28 +29 +30 +31 +32 +33 +34 +35 +36 +37 +38 +39 +40 +41 +42 +43 +44 +45 +46 +47 | |
Calculate the rising edge of a waveform. Errors if image or scalar provided.
+First, applies smoothing by taking weighted nearest and next-nearest +neighbour contributions to y values whose difference from their neighbours +is more than 0.2 times the total range in y. The global maximum y value is then +identified along with the first x position to the left of the peak where the y +value is less than or equal to half the global maximum. If all values of y to +the left of the peak are greater than half the global maximum, the position of +the global maximum is used. The value of x at this position is returned.
+ +builtins/rising.py25 +26 +27 +28 +29 +30 +31 +32 +33 +34 +35 +36 +37 +38 +39 | |
Brief descriptions of implementation details are available for all builtin functions. They are grouped into those which apply to Images and Waveforms (though some functions can be applied to either).
+ +