TCL Hypermesh syntax again: loop to store elements

Stéphane Combet

Hello,

Here again on my script, thanks to @Michael Herve and @Marc Arnold I go ahead little by little.

Now I try to store in a set some elements depending of their coordinates.

To simplify here, I have just a row of nodes, 2 rows of elements, and I would like to store elements only if their centerX is bigger than the X of the nodes.

I can't understant why my list $toKeepElems seems to remain empty with the following loop. I print the variables to see what happens and it seems it should be ok but at the end I have nothing with "puts $toKeepElems".

#Selecting nodes (user) and then elements connected to those nodes (with "by node id")

*createmarkpanel nodes 1 'Select Nodes'

set selectedNodes [hm_getmark nodes 1]

*createmark elems 1 "by node id" {*}$selectedNodes

set selectedElems [hm_getmark elems 1]

 

#Storing X coordinate of one of the nodes

set nodeA_id [lindex $selectedNodes 0]

set nodeA_xyz [join [hm_nodevalue $nodeA_id]]

set nodeA_x [lindex $nodeA_xyz 0]

 

#Creating an empty list to store elements

set toKeepElems {}

 

#Looping to store elements

foreach elemC $selectedElems {

set cx [hm_getvalue element id=$elemC dataname=centerx]

puts $cx

puts $nodeA_x

if {$cx > $nodeA_x} {

puts "We are in\n"

lappend $toKeepElems $elemC

}

}

 

#Displaying results

puts $selectedElems

puts $toKeepElems

 

Do you see where I am wrong?

Thanks!

 

Fred_Juras

Hi,

The issue is from the lappend command line. Actually, lappend expects a varname as first argument (without the $ for substitution). More details here: https://www.tcl.tk/man/tcl/TclCmd/lappend.html

So, just remove the $ in front of the toKeepElems variable (as below)  and your script should work as expected:

lappend toKeepElems $elemC

Regards,
Fred.

Fred_Juras

Hi,

The issue is from the lappend command line. Actually, lappend expects a varname as first argument (without the $ for substitution). More details here: https://www.tcl.tk/man/tcl/TclCmd/lappend.html

So, just remove the $ in front of the toKeepElems variable (as below)  and your script should work as expected:

lappend toKeepElems $elemC

Regards,
Fred.

Michael Herve_21439

Hello @Stéphane Combet ,

 

I see a typical tcl error in your command;. Please confirm if it is a typo error:

 

lappend $toKeepElems $elemC

 

lappend apply to the list entity itself, not the content in the list. So you should use instead

lappend toKeepElems $elemC

 

That said, from a performance point of view, if your intent is, for a first selection of elements, to isolate the elements whose x is greater than a value, you could use the following commands. That said, as xvalue in youer command above comes from one of the element node, not sure it can applied exactly this way.

 

*createmark elems 1 "by node id" {*}$selectedNodes

*createmark elems 2 "greater than or equal to value" centerx $xvalue

*markintersection elems 1 elems 2

set  toKeepElems [hm_getmark elems 1]

 

Best Regards,

Michael

Stéphane Combet

Frederic Juras_21782 said:

Hi,

The issue is from the lappend command line. Actually, lappend expects a varname as first argument (without the $ for substitution). More details here: https://www.tcl.tk/man/tcl/TclCmd/lappend.html

So, just remove the $ in front of the toKeepElems variable (as below)  and your script should work as expected:

lappend toKeepElems $elemC

Regards,
Fred.

Thank you @Frederic Juras that was the point!

Stéphane Combet

Michael Herve_21439 said:

Hello @Stéphane Combet ,

 

I see a typical tcl error in your command;. Please confirm if it is a typo error:

 

lappend $toKeepElems $elemC

 

lappend apply to the list entity itself, not the content in the list. So you should use instead

lappend toKeepElems $elemC

 

That said, from a performance point of view, if your intent is, for a first selection of elements, to isolate the elements whose x is greater than a value, you could use the following commands. That said, as xvalue in youer command above comes from one of the element node, not sure it can applied exactly this way.

 

*createmark elems 1 "by node id" {*}$selectedNodes

*createmark elems 2 "greater than or equal to value" centerx $xvalue

*markintersection elems 1 elems 2

set  toKeepElems [hm_getmark elems 1]

 

Best Regards,

Michael

Thank you Michael Herve this was the point!

I will take in consideration your performance suggestion, as my script is more complex in terms of orientation/coordinates I will see if I can use the "greater than or equal to value" filter.