Printing an Array Slice

The following macro prints a Fortran array slice. This macro, like other ones shown in this chapter, relies heavily on Tcl and uses unique CLI commands sparingly.

proc pf2Dslice {anArray i1 i2 j1 j2 {i3 1} {j3 1} {width 20}} {
    for {set i $i1} {$i <= $i2} {incr i $i3} {
        set row_out ""
        for {set j $j1} {$j <= $j2} {incr j $j3} {
            set ij [capture dprint $anArray\($i,$j\)]
            set ij [string range $ij \
                [expr [string first "=" $ij] + 1] end]
            set ij [string trimright $ij]
            if { [string first "-" $ij] == 1} {
                set ij [string range $ij 1 end] }
            append ij "                       "
            append row_out " " [string range $ij 0 $width] " "
        }
        puts $row_out
    }
}

After invoking this macro, the CLI prints a two-dimensional slice (i1:i2:i3, j1:j2:j3) of a Fortran array to a numeric field whose width is specified by the width argument. This width does not include a leading minus (-) sign.

All but one line is standard Tcl. This line uses the dprint command to obtain the value of one array element. This element's value is then captured into a variable. (dprint does not return a value. The CLI capture command allows a value that is normally printed to be sent to a variable.)

Here are several examples:

d1.<> pf2Dslice a 1 4 1 4
     0.841470956802     0.909297406673     0.141120001673    -0.756802499294
     0.909297406673    -0.756802499294    -0.279415488243     0.989358246326
     0.141120001673    -0.279415488243     0.412118494510    -0.536572933197
    -0.756802499294     0.989358246326    -0.536572933197    -0.287903308868
d1.<> pf2Dslice a 1 4 1 4 1 1 17
     0.841470956802     0.909297406673     0.141120001673    -0.756802499294
     0.909297406673    -0.756802499294    -0.279415488243     0.989358246326
     0.141120001673    -0.279415488243     0.412118494510    -0.536572933197
    -0.756802499294     0.989358246326    -0.536572933197    -0.287903308868
d1.<> pf2Dslice a 1 4 1 4 2 2 10
     0.84147095     0.14112000 
     0.14112000     0.41211849 
d1.<> pf2Dslice a 2 4 2 4 2 2 10
    -0.75680249     0.98935824 
     0.98935824    -0.28790330 
d1.<>