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Abteilung Astronomie

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plot Source code in cafe_plot.pro


           plots data/model of fit
           plot [,top][,bottom|panelnum][,/quiet][,/noerase]
Input Parameters
           top      - (optional) Defines the plot type to draw in the upper
                      part of the plot window.
           bottom   - (optional) Defines the plot type to draw in the lower
                      part of the plot window.
           panelnum - If instead of bottom a integer number is given
                      the panel with this number is set (starting
                      from 0).
           The plots to be inserted in the top/bottom
                      panels are defined with plot types defining
                      what to plot. There are some plot types
                      available (and could be extended just as in
                      case of fit models).
                               > [+|-]<plot type>["[parameter]"][:group]...
                               > ...[+<plot type>["[parameter]"][:group]]
                           - add/remove:If the plot type is prepended
                                        with "+" the new plot types
                                        are added to the current
                                        If the plot type is prepended
                                        with "-" this plot type is
                                        removed. For this case
                                        wildcards are allowed to
                                        remove more than one plot
                                        > plot,data+model
                                        > plot,-mod*
                                        -> remove the model plot type.
                           - plot type: defining what to plot (refer below)
                           - parameter: defining special options to
                                        be passed to the plot type
                                        driver. These are usually
                                        those accepted by the IDL
                                        oplot command, e.g. linestyle.
                                        The format is:
                                        keyword=value. It is possible
                                        to define several such
                                        parameters which must be
                                        separated by ";".
                                        If the assignment "=value" is
                                        not given the value =1 will
                                        be used (setting flags).
                                          plot, data[linestyle=3;psym=-4;noerror]
                                        Remark: Options set with
                                        setplot override these parameters.
                            - group:    Defines for the plot type
                                        which data group to use. This
                                        allows to plot several groups
                                        in a single plot window.
                               > plot, data+model...
                                 -> Draw data and model in the same
                               > plot, data:2+data:3
                                 -> Draw data from group 2,3 to panel.
                               > plot, data[linestyle=3;psym=-3]+model
                                 -> Draw data plus underlying model,
                                    which is formated with different symbol/linestyle.
                      The "+" adds several plot types in the same
                      panel. In this case each will be drawn in a
                      different color (refer also to the plot types
                      The optional ":<group>" defines the group for
                      the specific plot type to look data/model for.
                      Common plot types are
                            "data" - draw the data as is
                            "model"- draw the computed model with
                                     current parameters
                             "res" - Residuum between data/model
                             "delchi" - Same but in units of 1 sigma
                      Available plot types can be listed with the
                      while a specific plot type can be shown with
                      the command
                               help,plot,<plot type>.
           /quiet    - Do not print plot informations.
           /noeraase - Do not delete window (useful for plotting as
                       a client procedure)
           All options may be set with the "set" command. The
           command prefix is "plot".
                      Plotting may be influenced by some general plot
                      parameters set with the setplot command. For all
                      plot styles following setplot identifier will be
                      applicable (and must be defined for plot panel 0):
             weight  - A integer number which defines how  the
                       height should be distributed among different
                       panels. For this all weights are summed up;
                       and each panel gets a share according its
                       weight from the total sum. For example with
                       top panel of weight 2 and bottom panel of
                       weight 1 will set 2/3 of the available height
                       at top panel and 1/3 at bottom panel (this is
                       the default).
             topsep  - Floating number between 0..1 defining margin
                       of plot to top (either frame or plot above).
                       This must include sufficient place for
                       title/subtitle text.
                       Default is 0.05.
          bottomsep  - Floating number between 0..1 defining margin
                       of plot to bottom (either frame or plot below).
                       This must include sufficient space for x-axis
                       Default is 0.1.
            rmargin  - Floating number between 0..1 defining margin
                       of plot to right side.
                       This must include sufficient space for right y-axis
                       text (if any).
                       Default is 0.05.
            lmargin  - Floating number between 0..1 defining margin
                       of plot to left side.
                       This must include sufficient space for left y-axis
                       text/tick labels.
                       Default is 0.1.
            xfree    - Flag (0/1). If set the x-range is computed
                       independent for each panel (not recommended for
                       interactive plot tools, e.g. iplot/wplot).
                       Default is off (0).
            position - 4-vector containing edge coordinates
                       of panel to plot. Coordinates are values
                       between 0..1.
                       Setting this option overrides the default
                       algorith using the top/bottomsep/r/lmargin and
                       weigth keywords described above.
          background - The background color for all plots. This is
                       common for all panels and can not be set
                       separately :-<
          startcolor - First color number used to plot
                       frame/data. Must be adapted to currently used
                       color table. Default: 255.
          deltacolor - Decrease of color to apply for distinct plot
                       types/data sets. Default: 23.
      startlinestyle - First line style used to plot frame/data. Default: 0.
                       Must not exceed 5.
      deltalinestyle - Increase of line styles for distinct plot
                       types/data sets. May be positive or negative
                       integer number. Default: 0 (no change).
           startpsym - First point symbol used to plot frame/data. Default: -4.
                       Should not exceed -7..7. If psym is negative
                       lines are drawn, if positive, not (refer IDL
                       PLOT command).
                       Userdefined symbols (8) are not supported.
           deltapsym - Increase of point symbols for distinct plot
                       types/data sets. May be positive or negative
                       integer number. Default: 0 (no change).
                       If psym exceeds -7..7 during plot different
                       plot types it will be set at 0 (no symbol). Therefore
                       plotting all data sets with lines it is
                       recomended to set deltapsym at a negative
                       value (to decrease and restart from 0).
          zbuff      - Use the Z Buffer device for plot
                       production. The practical use is for 3-dim
                       plots. The Z Buffer device essentially is able
                       to check which object (even axis lines, text
                       or data) is behind another object and must not
                       be drawn. This is especially usefull when:
                        - Combining several shaded objects, possibly
                          with surface or contour.
                        - Generating high quality plot 3-dim plot
                       The drawback is that the generated
                       (postscript) images are pixelated, i.e. the
                       quality depends on the resolution/image size.
                       Also fonts are not always drawn properly.
                       This means: If one prints zbuffer generated
                       plots into a file she has to look
                        - reasonable resolution (s.b.)
                        - A proper line thickness (setplot keywords
                          thick, xthick,ythick,zthick).
                        - A scaleable font. System fonts usually look
                          poor. It is recomended to use the setplot
                          keyword font=1.
           maxres    - Using the Z Buffer device with this keyword defines
                       the maximal number of pixels in X
                       direction. Default are 5000. The pixel in Y
                       direction are set according the plot aspect
           tex       - Use TexToIDL to convert the parameter text
                       from TeX syntax into IDL strings. This allows
                       to access mathematical symbols like \chi=Chi,
                       \Delta,\pi etc.
                       It is recomended to use this parameter
                       instead of calling textoidl() manually. The
                       latter causes problems when printing into
                       postscript files because the IDL codes for
                       plot fonts (!p.font = -1) and hardware fonts
                       (!p.font = 0) are different.
           enhanced  - Switch on enhanced plot facilities (see
                       ENHANCED PLOTTING).
           Enhanced plotting is intended for 2-D plotting only
           (because 1-D plots do not need to shade/mask/combine
           The plot may be a combination of different separate plot
           images. This feature is enabled using the "enhanced"
           keyword. After this some plot operators are available
           which take each plot type as a separate unit which can be
           combined to create complex images. In standard mode only
           the "+" operator is available which simply overlays
           several plot images. In enhanced mode following operators
           are implemented:
           + - standard case: execute plot type on current plot
               device. This is the only operator which acknowledges
               the z buffer device.
           ^ - add two images in respect of their colors. May be used
               to simulate transparency by adding image parts which
               were hidden.
           * - multiply colors of image. May be used to
               enhance/diminish colors. It is possible to multiply an
               image with a number to change the color space.
           & - mask parts of image. This means that for a & b the
               image b is shown where image b is not background
               color, otherwise a is shown. Usefull to replace parts
               of image with other parts.
           There are some additional keyword parameters which can be
           used to influence the plot result:
           ctable  - Defines the color table to use. Therefore a plot
                     may consist of plot images created with
                     different color tables ;-)
        background - Defines the background color for which the plot
                     is considered to be transparent. This is
                     important for the "&" - Operator to mask certain
                     parts of the image.
           The enhanced mode may be used to circumvent problems
           arising from Z Buffer use. A detailed tutorial is
           described at: http://www.sljus.lu.se/stm/IDL/Surf_Tips/ by
           Struan Gray.
           Here some basic examples:
           > setplot,enhanced
           > setplot,zbuff
           > plot,data2[shade] & data2[surf]
           -> avoid submarining of surface lines in shade
              plot. Actually the surface *replaces* the shade.
           > plot,data[shade]:0*0.5 ^ data2[shade]:1*0.5
           -> plot data sets of group 0 and 1 in a transparent manner
           > plot,data2[shade,ctable=1]:0+data2[shade,shading=0]:1 ^
           >      data2[shade,ctable=3]:1+data2[shade,shading=0]:0
           -> plot data set 0 in blue color and data set 1 in red
              color, masking each other.
           The enhanced mode has some drawbacks. One is that is
           significant slower than the standard mode (because each
           image must be read and processed separately).
           The other problem arises from the fact that the image
           always is pixellated; plotting out to a postscript device
           results in the same problems as the use of the Z-Buffer
           device (which should be used in enhanced mode anyway).
Side Effects
           Last plot ranges/plot type will be stored if no new is
           > plot, data,delchi
                -> plot data and chi difference in different panels.
Revision History
           $Id: cafe_plot.pro,v 1.34 2004/07/30 15:52:36 goehler Exp $

Last modified by pro2html on 2005 January 04 at 16:13 UTC

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Jörn Wilms (wilms@astro.uni-tuebingen.de)
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