Difference between revisions of "Data Manipulation Functions"

From LIBISIS
Jump to navigation Jump to search
Line 15: Line 15:
 
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].  
 
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].  
  
<pre> >> shift_x(ww, xshift)
+
<pre>>> shift_x(ww, xshift)
 
>> shift_y(ww,yshift)
 
>> shift_y(ww,yshift)
 
>> shift_xy(ww,xshift,yshift)</pre>
 
>> shift_xy(ww,xshift,yshift)</pre>
Line 69: Line 69:
  
 
==Flip Functions==
 
==Flip Functions==
All data, including associated signal and error data is reversed in the order it appears in the dataset.
+
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].
 +
 
 +
 
 +
<pre>>> flip_x(ww)</pre>
 +
 
 +
Reverses the order of x columns in [[IXTdataset_2d]]
 +
 
 +
 
 +
<pre>>> flip_y(ww)</pre>
 +
 
 +
Reverses the order of y rows in [[IXTdatset_2d]]
 +
 
 +
<pre>>> flip(ww)
 +
>> flip(w)</pre>
 +
 
 +
Reverses the order of x rows in [[IXTdataset_1d]] or both x columns and y rows in [[IXTdataset_2d]].

Revision as of 16:23, 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)
>> shift(w, 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.

>> 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)

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.