MDLPL_EXT.
                           °°°°°°°°°°
  MDLPL_EXT  displays at the graphic window plot of the estimates of 
  the segmented parameters. You should select plot type and station.
  Deselected stations are not displayed.

  To select the station either enter the number (but not exceeding 9) or 
position cursor at the station box and then click <Left/Mouse>. To move to 
the next station hit N. Station name is ignored when EOP plot is displayed.

  To select plot type either hit the plot type code (C, T, M, Z, Y, U) or 
position cursor at the plot type box and then click <Left/Mouse>. 
 
  To display the plot either hit P or position cursor at the light green box 
and then click <Left/Mouse>. 

  To abort MDLPL_EXT and come back to OPTIN either hit X or click <Right/Mouse>

                Summary of commands usage:

<Left/Mouse>    Select the box with station name or plot type
<Middle/Mouse>  Select the box with station name or plot type
<Right/Mouse>   Abort making further plots and to return to OPTIN
             C  Set plot type "Piece-wise component of clock function"
             M  Set plot type "Atmosphere piece-wise path delay"
             N  Move to the next station.
             P  Display plot at the graphic window
             T  Set plot type "Total clock function"
             U  Set plot type "Piece-wise UT1"
             ?  Display help information.
             X  Abort making further plots and to return to OPTIN
             Y  Set plot type "Piece-wise Y pole coordinate"
             Z  Set plot type "Piece-wise X pole coordinate"

Comments:

1) Box with clock reference station has red frame. It is useless to make 
   plots of clock function for this station.

2) Total clock function will not been displayed in the case when non uniform
   clocks interval have been chosen.

3) Box with EOP plot type will have red frame in the case when EOP was 
   modeled by polynomial, but not as piece-wise linear function. It is
   useless to make plot of EOP in that case.

4) Black line depicted in the plot of EOP represents reference high-frequency
   EOP model. The model identifier is declared in ../mdlpl/mdlcm.i : variable
   HFEOP_CMP_DEF. Permanent shift is added to the model value to match the first
   and the last points of the EOP estimates and model values. Blue line in 
   the plot of EOP represents the high-frequency EOP model which has been used
   as a priori model for calculation theoreticals. It will not been seen in the
   case when it coincides with reference hf EOP model.

5) Hints how to customize MDLPL_EXT graphic window may be found in 
   $HELP_DIR/diagi_1.hlp