sddscontour

• description: sddscontour makes contour and color-map plots from an SDDS data set column, or from a rpn expression in terms of the values in the columns of a data set. It supports FFT interpolation and filtering. If the data set contains more than one data page, data from successive pages is plotted on separate pages.

• example: This will generate a two-dimensional color-shaded map of the function on the region x:[-1, 1] and y:[-1, 1]:
  sddscongen example.sdds -xRange=-1,1,101 -yRange=-1,1,101
  -zEquation="x x * y y * + 4 * pi * sin"
  sddscontour example.sdds -shade example.sdds -equalAspect
• synopsis:
  sddscontour SDDSfilename switches
• switches:
  • Choice of what to plot:
    [-quantity=columnName | -equation=rpnExpression | -columnMatch=indepColumnName,matchingExpression]
    • quantity -- Specifies the name of the column to make a contour or color map of.
    • equation -- Specifies a rpn expression to make a contour or color map of. The expression may refer to the values in the columns by the appropriate column name, and may also refer to the variable values by name.
    • columnMatch -- Specifies plotting of all columns matching matchingExpression as a function of the column indepColumnName. Each matching column is displayed as a horizontal color bar.

    In the case of the first two choices, the file must contain tabular data with at least one numeric column, which will be organized into a 2d array with R rows and C columns. By default, the values are assumed to come in row-major order (i.e., the file should contain a series of R sequences each containing the C values of a single row). The parameters of the 2d grid over which the plot is to be made are communicated to the program in one of two ways:

    1. The string parameters Variable1Name and Variable2Name contain the names of the x and y axis variables, which I'll represent as x and y respectively. The program expects to find six more parameters, with names xMinimum, xInterval, and xDimension, and similarly for y. These parameters must be numeric, and contain the minimum value, the interval between grid points, and the number of points, respectively, for the dimension in question. The data must be arranged so that y varies fastest as the row in the file increases. Put another way, variable 1 is the row index and variable 2 is the column index.
    2. The numeric parameters NumberOfRows and NumberOfColumns contain the values of R and C, respectively.

  • rpn control:
    [-rpnDefinitionsFiles=filename[,filename...]] [-rpnExpressions=setupExpression[,setupExpression...]]
    • rpnDefinitionsFiles -- Specifies the names of files containing rpn expressions to be executed before any other processing takes place.
    • rpnExpressions -- Specifies rpn expressions to be executed before any other processing takes place, immediately after any definitions files.
  • Shade and contour control:
    {-shade=number[,min,max] | -contours=number[,min,max]} [-labelContours=interval[,offset]]
    • shade -- Specifies that a color (or grey-scale) map should be produced, with the indicated number of shades mapped onto the range from min to max. If min and max are not given, they are taken to be equal to the minimum and maximum data values.
    • contours -- Specifies that contour lines should be drawn, with the indicated number of lines for the range from min to max. If min and max are not given, they are taken to be equal to the minimum and maximum data values.
    • labelContours -- Specifies that every interval contour line, starting with the offset line, should be labeled with the contour value.
  • Image processing:
    [-interpolate=nx,ny[,floor | ceiling | antiripple]] [-filter=xcutoff,ycutoff]
    • interpolate -- Specifies that the 2d map should be interpolated to have nx times more rows (or x grid points) and ny times more columns (or y grid points). Since FFTs are used to do the interpolation, the original number of grid points must be a power of 2, as must the factor. Giving a factor of 1 disables interpolation for the dimension in question. floor, ceiling, and antiripple specify image processing of the interpolated map. floor and ceiling respectively force values below (above) the minimum (maximum) value of the data to be set equal to that value. antiripple causes the map to be altered so that non-zero values in the new map between zero values on the original map are set to zero; this suppresses ripples that sometimes occur in regions where the data was originally all zero.
    • filter -- Applies low-pass filters to the data with the specified normalized cutoff frequencies. The integer cutoff values give the number of frequencies starting at the Nyquist frequency that are to be eliminated.
  • Plot labeling:
    [-xLabel=string] [-yLabel=string] [-title=string] [-topline=string] [-topTitle] [-noLabels] [-noScales] [-dateStamp]
    • xLabel, yLabel, title, topline -- These specify strings to be placed in the various label locations on the plot.
    • topTitle -- Requests that the title label be placed at the top of the plot, rather than at the bottom.
    • noLabels -- Requests that no labels be placed on the plot.
    • noScales -- Requests omission of the numeric scales.
    • noBorder -- Requests omission of the border around the data. Implies -no_scales.
    • dateStamp -- Requests that the date and time be placed on the pot.
  • Data scaling:
    [-deltas[={fractional | normalize}]] [-logscale[=floor]]
    • deltas -- For use with -columnMatch option only. Specifies plotting only differential values (relative to the mean of each column). If the fractional qualifier is given, then the differential values normalized to the individual means are plotted. If the normalize qualifier is given, then all differential values are normalized to the range [-1, 1] before plotting.
    • logscale -- Specifies plotting the base-10 logarithm of the values. If a floor value is given, it is added to each value prior to taking the logarithm; this can help prevent taking the log of zero, for example.
  • Miscellaneous plot control:
    [-scales=xl,xh,yl,yh] [-device=name[,deviceArguments]] [-swapxy] [-equalAspect[=-1,1]] [-noBorder]
    • scales -- Specifies the extent of the plot region.
    • device -- Specifies the device name and optional device-specific arguments.
    • swapxy -- Requests that the horizontal and vertical coordinates be interchanged.
    • equalAspect -- Requests plotting with an aspect ratio of 1. If the '1' qualifier is given, then the aspect ratio is achieved by changing the size of the plot region within the window; this is the default. If the '-1' qualifier is given, then the aspect ratio is achieved by changing the size of the plot region in user's coordinates.
    • noBorder -- Specifies that no border will be placed around the graph.
  • Miscellaneous:
    [-output=filename] [-verbosity[=level]]
    • output -- Requests SDDS output of a new file containing the data with any modifications resulting in the processing requested.
    • verbosity -- Sets the verbosity level of informational printouts. Higher integer values of the level parameter result in more output.
• see also:
  • sddscongen
  • sddshist2d
  • sddsplot
  • rpn
• author: M. Borland, ANL/APS.