Data Manipulation Functions

Data manipulation functions change the data in some way, such as scaling or flipping it. The functions available are

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 IXTdataset_2d object
• Output is an IXTdataset_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 IXTdataset_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 IXTdataset_2d

>> flip(ww)
>> flip(w)

Reverses the order of x rows in IXTdataset_1d or both x columns and y rows in IXTdataset_2d.

Arrays of Datasets

If an array of dataset objects is passed to the function, then the operation is performed on each dataset in turn.

Example:

>> wout = flip(w)

is equivilent to

for i = 1:length(w)
   wout(i) = flip(w(i))
end