Difference between revisions of "Data Manipulation Functions"
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==Scale Functions== | ==Scale Functions== | ||
− | Multiplies one of the independent variable arrays (x or y) by a constant. | + | Multiplies one of the independent variable arrays (x or y) by a constant. For instance if an x array, [10, 20, 30, 40, 50], is scaled by 2 the output x array will be [20, 40, 60, 80, 100]. |
<pre>>> wwout = scale_x(w, xscale) | <pre>>> wwout = scale_x(w, xscale) |
Revision as of 16:27, 17 March 2008
Data manipulation functions change the data in some way, such as scaling or flipping it. The functions available are
>> wnew = shift(w, xshift) >> wwout = shift_x(ww, xshift) >> wwout = shift_y(ww, yshift) >> wwout = shift_xy(ww, xshift, yshift) >> wout = scale(w, factor) >> wwout = scale_x(ww, factor) >> wwout = scale_y(ww, factor) >> wout = flip(w) >> wwout = flip_x(ww) >> wwout = flip_y(ww)
Shift Functions
These functions add a value to one of the independent variable arrays (x or y), leaving any related data (such as the signal data) untouched. For instance if an x array, [10, 20, 30, 40, 50], is shifted by 2 the output x array will be [12, 22, 32, 42, 52].
>> shift_x(ww, xshift) >> shift_y(ww,yshift) >> shift_xy(ww,xshift,yshift)
- Input is an IXTdataset_2d object
- Output is an IXTdataset_2d object
- Shifts x data by amount xshift
- Shifts y data by amount yshift
>> shift(w, xshift)
- Input is an IXTdataset_1d object
- Output is an IXTdataset_1d object
- Shifts x data by amount xshift
Example:
>> wout = shift_x(ww, 4)
Every x value in wout will have 4 added to them
Scale Functions
Multiplies one of the independent variable arrays (x or y) by a constant. For instance if an x array, [10, 20, 30, 40, 50], is scaled by 2 the output x array will be [20, 40, 60, 80, 100].
>> wwout = scale_x(w, xscale) >> wwout = scale_y(ww, yscale) >> wwout = scale(ww, xyscale)
- Input is an IXT_dataset_2d object
- Output is an IXT_dataset_2d object
- Scales x by factor xscale
- Scales y by factor yscale
- Scales both x and y by amount xyscale
>> wout = scale(w, xscale)
- Input is an IXTdatset_1d object
- Output is an IXTdataset_1d object
- scales x by an amount xscale
Example:
>> wwout = scale_y(ww, 4)
will multiply every y value in wwout by 4
Flip Functions
All data, including associated signal and error data is reversed in the order it appears in the dataset. For instance if a dataset has x data [1, 2, 3, 4], signal data [34, 35, 36, 37] and error data [0.1 0.2 0.1 0.1] then the flipped data will have xdata [4, 3, 2, 1], signal data [37, 36, 35, 34] and error data [0.1 0.1 0.2 0.1].
>> flip_x(ww)
Reverses the order of x columns in IXTdataset_2d
>> flip_y(ww)
Reverses the order of y rows in IXTdatset_2d
>> flip(ww) >> flip(w)
Reverses the order of x rows in IXTdataset_1d or both x columns and y rows in IXTdataset_2d.