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Class: GridData Gnuplot/PlotItems.py

Holds data representing a function of two variables, for use in splot.

GridData represents a function that has been tabulated on a rectangular grid. The data are written to a file; no copy is kept in memory.

Base Classes   
PlotItem
Methods   
__init__
pipein
  __init__ 
__init__ (
        self,
        data,
        xvals=None,
        yvals=None,
        binary=1,
        inline=_unset,
        **keyw,
        )

GridData constructor.

Arguments:

data
the data to plot: a 2-d array with dimensions (numx,numy).
xvals
a 1-d array with dimension numx
yvals
a 1-d array with dimension numy
binary=<bool>
send data to gnuplot in binary format?
inline=<bool>
send data to gnuplot "inline"?

Note the unusual argument order! The data are specified before the x and y values. (This inconsistency was probably a mistake; after all, the default xvals and yvals are not very useful.)

data must be a data array holding the values of a function f(x,y) tabulated on a grid of points, such that 'data[i,j] == f(xvals[i], yvals[j])'. If xvals and/or yvals are omitted, integers (starting with 0) are used for that coordinate. The data are written to a temporary file; no copy of the data is kept in memory.

If binary=0 then the data are written to a datafile as x y f(x,y) triplets (y changes most rapidly) that can be used by gnuplot's splot command. Blank lines are included each time the value of x changes so that gnuplot knows to plot a surface through the data.

If binary=1 then the data are written to a file in a binary format that splot can understand. Binary format is faster and usually saves disk space but is not human-readable. If your version of gnuplot doesn't support binary format (it is a recently-added feature), this behavior can be disabled by setting the configuration variable gp.GnuplotOpts.recognizes_binary_splot=0 in the appropriate gp*.py file.

Thus if you have three arrays in the above format and a Gnuplot instance called g, you can plot your data by typing g.splot(Gnuplot.GridData(data,xvals,yvals)).

Exceptions   
Errors.DataError( 'The size of xvals must be the same as the size of ' 'the first dimension of the data array' )
Errors.DataError( 'The size of yvals must be the same as the size of ' 'the second dimension of the data array' )
Errors.DataError( 'data array must be two-dimensional' )
Errors.OptionError( 'binary inline data not supported' )
  pipein 
pipein ( self,  f )


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