# PSMECA with -Sx|y option

**URL:** <https://forum.generic-mapping-tools.org/t/psmeca-with-sx-y-option/1939>\
**Category:** Q&A\
**Created:** [July 30, 2021, 1:44am UTC](https://forum.generic-mapping-tools.org/t/psmeca-with-sx-y-option/1939 "2021-07-30T01:44:38Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![Rino\_Salman](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/rino_salman/32/1462_2.png) [@Rino\_Salman](https://forum.generic-mapping-tools.org/u/Rino_Salman)\
**Post date:** [July 30, 2021, 1:44am UTC](https://forum.generic-mapping-tools.org/t/psmeca-with-sx-y-option/1939/1 "2021-07-30T01:44:38Z")

</div>

Dear GMT developers and users,

I am going to plot a focal mechanism using parameters on the attachment (Table A2.png, solution no.61). My understanding, based on the documentation here: [http://gmt.soest.hawaii.edu/doc/5.4.5/supplements/meca/psmeca.html](http://gmt.soest.hawaii.edu/doc/5.4.5/supplements/meca/psmeca.html), I have to use psmeca with -Sx|y option. But, my attempts have had no luck so far.

Based on the information in Table A2, my data is:  
118.8 -3.1 13 4\*10e+23 73 68 344 0 253 22 25

The script I tried:  
grep -v “#” Fitch1969.txt | psmeca -J -R -Sx2 -O -Groyalblue -K -T \>\> $psFile  
or  
grep -v “#” Fitch1969.txt | psmeca -J -R -Sy2 -O -Groyalblue -K -T \>\> $psFile

I use GMT version 5.4.5

The intended focal mechanism is shown in the attachment (focal\_mechanism\_sol.61.png).  
I appreciate your help.

Cheers,  
Rino

 ![Table A2](https://canada1.discourse-cdn.com/flex047/uploads/gmt/original/2X/4/49520579c68a890293958c1010cba0aca5080ff6.png) ![focal_mechanism_sol.61](https://canada1.discourse-cdn.com/flex047/uploads/gmt/original/2X/3/32d1d94b6cc887ee44763c1f76edacc853c29faf.png)

---

<div class="post-metadata">

**Author:** ![EJFielding](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/ejfielding/32/82_2.png) [@EJFielding](https://forum.generic-mapping-tools.org/u/EJFielding)\
**Post date:** [August 1, 2021, 9:14pm UTC](https://forum.generic-mapping-tools.org/t/psmeca-with-sx-y-option/1939/2 "2021-08-01T21:14:08Z")

</div>

Hi Rino,

I think you could try to use the `-Sp` option because you have partial information on the moment tensor, but you also would need to calculate the strikes and dips of the two planes from the poles to the planes.

++Eric

---

<div class="post-metadata">

**Author:** ![Rino\_Salman](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/rino_salman/32/1462_2.png) [@Rino\_Salman](https://forum.generic-mapping-tools.org/u/Rino_Salman)\
**Post date:** [August 1, 2021, 10:45pm UTC](https://forum.generic-mapping-tools.org/t/psmeca-with-sx-y-option/1939/3 "2021-08-01T22:45:25Z")

</div>

Hi Eric,

Thanks for the clue.

Cheers,  
Rino