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Hi Jose,</div>
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I could now do matrix exponential but facing a problem with a complex matrix. In particular, I want to do \exp(-itH), where H is a Hamiltonian. How to implement this?</div>
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Thanks,
<div>Sanku</div>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> Jose E. Roman <jroman@dsic.upv.es><br>
<b>Sent:</b> Friday, September 3, 2021 2:53 PM<br>
<b>To:</b> Paul, Sanku <paulsank@msu.edu><br>
<b>Cc:</b> PETSc <petsc-users@mcs.anl.gov><br>
<b>Subject:</b> Re: [petsc-users] Matrix exponential</font>
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<div class="PlainText">Please always reply to the list (Reply-All), not to myself.<br>
<br>
You should be able to convert from a scipy sparse matrix to a PETSc matrix via PETSc.Mat().createAIJWithArrays(). Don't know how if there is any example in the petsc4py documentation.<br>
<br>
Jose<br>
<br>
<br>
> El 3 sept 2021, a las 20:26, Paul, Sanku <paulsank@msu.edu> escribió:<br>
> <br>
> Dear Jose,<br>
> <br>
> Thank you very much for your help. I have another question can we just simply pass a sparse.csr.matrix to A. For instance, if B is the sparse.csr.matrix can we do A=B.copy(). Or do I have to do it in a different way?<br>
> <br>
> Best,<br>
> Sanku<br>
> From: Jose E. Roman <jroman@dsic.upv.es><br>
> Sent: Friday, September 3, 2021 2:13 PM<br>
> To: Paul, Sanku <paulsank@msu.edu><br>
> Cc: petsc-users@mcs.anl.gov <petsc-users@mcs.anl.gov><br>
> Subject: Re: [petsc-users] Matrix exponential<br>
> <br>
> You should either create the FN object and then<br>
> <br>
> E.setFN(F)<br>
> <br>
> or extract the FN object and assign to a variable<br>
> <br>
> F = E.getFN()<br>
> <br>
> You can see an example in $SLEPC_DIR/src/binding/slepc4py/demo/ex6.py<br>
> <br>
> <br>
> Jose<br>
> <br>
> <br>
> > El 3 sept 2021, a las 19:53, Paul, Sanku <paulsank@msu.edu> escribió:<br>
> > <br>
> > Dear Sir/Ma'am,<br>
> > <br>
> > I am trying to use SLEPc to calculate matrix exponential in my python code but I am not getting the correct result. I have attached the code. Could you let me know what I am doing wrong. This is my first time using SLEPc. So, I would like to ask you
if you could send me a tutorial on matrix exponential using SLEPc in python code.<br>
> > <br>
> > Best,<br>
> > Sanku<br>
> > <ex2.py><br>
<br>
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