Difference between revisions of "Data Manipulation Functions"
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Data manipulation functions change the data in some way, such as scaling or flipping it. The functions available are | Data manipulation functions change the data in some way, such as scaling or flipping it. The functions available are | ||
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==Shift Functions== | ==Shift Functions== | ||
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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]. | ||
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| − | '''Example:''' | + | '''''Example:''''' |
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| + | <pre> >> wout = shift_x(ww, 4)</pre> | ||
Every x value in wout will have 4 added to them | Every x value in wout will have 4 added to them | ||
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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) | ||
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>> wwout = scale(ww, xyscale)</pre> | >> wwout = scale(ww, xyscale)</pre> | ||
| − | * Input is an [[ | + | * Input is an [[IXTdataset_2d]] object |
| − | * Output is an [[ | + | * Output is an [[IXTdataset_2d]] object |
* Scales x by factor xscale | * Scales x by factor xscale | ||
* Scales y by factor yscale | * Scales y by factor yscale | ||
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<pre>>> wout = scale(w, xscale)</pre> | <pre>>> wout = scale(w, xscale)</pre> | ||
| − | * Input is an [[ | + | * Input is an [[IXTdataset_1d]] object |
* Output is an [[IXTdataset_1d]] object | * Output is an [[IXTdataset_1d]] object | ||
* scales x by an amount xscale | * scales x by an amount xscale | ||
| − | '''Example:''' | + | '''''Example:''''' |
| + | <pre>>> wwout = scale_y(ww, 4)</pre> | ||
| − | + | will multiply every y value in wwout by 4 | |
| − | + | ==Flip Functions== | |
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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]. | 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]. | ||
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<pre>>> flip_y(ww)</pre> | <pre>>> flip_y(ww)</pre> | ||
| − | Reverses the order of y rows in [[ | + | Reverses the order of y rows in [[IXTdataset_2d]] |
<pre>>> flip(ww) | <pre>>> flip(ww) | ||
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Reverses the order of x rows in [[IXTdataset_1d]] or both x columns and y rows in [[IXTdataset_2d]]. | Reverses the order of x rows in [[IXTdataset_1d]] or both x columns and y rows in [[IXTdataset_2d]]. | ||
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| + | == Arrays of Datasets == | ||
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| + | If an array of dataset objects is passed to the function, then the operation is performed on each dataset in turn. | ||
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| + | '''''Example:''''' | ||
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| + | <pre>>> wout = flip(w)</pre> | ||
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| + | is equivilent to | ||
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| + | <pre>for i = 1:length(w) | ||
| + | wout(i) = flip(w(i)) | ||
| + | end</pre> | ||
Latest revision as of 14:04, 1 April 2008
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