Hi,
when I try to define a complex Hamiltonian (e.g. some extended Heisenberg-model with Sx _and_ Sy=-I/2(Splus-Sminus) couplings to external fields) fulldiag or other ALPS-programs end with the error "can not convert complex number into real one"
Is this a general restriction for ALPS, or did I miss some configuration or compile option? If not - do you know any patch or work-around to enable complex-numbers?
Thanks in advance and greetings, Sebastian
Hi Sebastian,
, have you tried setting the parameter COMPLEX to true? This might work for the fulldiag, sparsediag and dmrg programs.
Matthias
On Apr 30, 2010, at 9:37 AM, Sebastian Greschner wrote:
Hi,
when I try to define a complex Hamiltonian (e.g. some extended Heisenberg-model with Sx _and_ Sy=-I/2(Splus-Sminus) couplings to external fields) fulldiag or other ALPS-programs end with the error "can not convert complex number into real one"
Is this a general restriction for ALPS, or did I miss some configuration or compile option? If not - do you know any patch or work-around to enable complex-numbers?
Thanks in advance and greetings, Sebastian
Hi,
I am having some trouble with the dmrg-program (e.g. of current ALPS 2.0b3) and "complex-valued" models. It seems to me that dmrg ignores the imaginary part of model-parameters (even with COMPLEX set to true). "sparsediag" gives the correct results.
Is this a bug or a general restriction of the dmrg-program? Or is it just a problem of my model or my local installation?
Thanks in advance and greetings, Sebastian
On 22 Jul 2010, at 05:33, Sebastian Greschner wrote:
Hi,
I am having some trouble with the dmrg-program (e.g. of current ALPS 2.0b3) and "complex-valued" models. It seems to me that dmrg ignores the imaginary part of model-parameters (even with COMPLEX set to true). "sparsediag" gives the correct results.
Is this a bug or a general restriction of the dmrg-program? Or is it just a problem of my model or my local installation?
Thanks in advance and greetings, Sebastian
Hi Sebastian,
I fixed one bug and the fix will show up in the MacOS and source versions of thennext nightly snapshot (Friday morning). Can you please try that?
Matthias
Hi Matthias,
Thank you - now dmrg gives the correct results!
Unfortunately there is still one (but probably unrelated) problem with dmrg (I am working on a Debian Lenny system - Intel Xeon): Depending on the parameters I choose (some special model parameters, Number of MAXSTATES, etc.) in the parameter file, I sometimes get segmentation faults at the beginning or at the end. Sorry - I haven't figured out yet, when this happens exactly, but maybe somebody has observed similar errors...
Best, Sebastian
On 22/07/10 17:25, Matthias Troyer wrote:
On 22 Jul 2010, at 05:33, Sebastian Greschner wrote:
Hi,
I am having some trouble with the dmrg-program (e.g. of current ALPS 2.0b3) and "complex-valued" models. It seems to me that dmrg ignores the imaginary part of model-parameters (even with COMPLEX set to true). "sparsediag" gives the correct results.
Is this a bug or a general restriction of the dmrg-program? Or is it just a problem of my model or my local installation?
Thanks in advance and greetings, Sebastian
Hi Sebastian,
I fixed one bug and the fix will show up in the MacOS and source versions of thennext nightly snapshot (Friday morning). Can you please try that?
Matthias
Hi Sebastian,
can you please post an example parameter file that segfaults at the beginning?
Matthias
On 23 Jul 2010, at 03:53, Sebastian Greschner wrote:
Hi Matthias,
Thank you - now dmrg gives the correct results!
Unfortunately there is still one (but probably unrelated) problem with dmrg (I am working on a Debian Lenny system - Intel Xeon): Depending on the parameters I choose (some special model parameters, Number of MAXSTATES, etc.) in the parameter file, I sometimes get segmentation faults at the beginning or at the end. Sorry - I haven't figured out yet, when this happens exactly, but maybe somebody has observed similar errors...
Best, Sebastian
On 22/07/10 17:25, Matthias Troyer wrote:
On 22 Jul 2010, at 05:33, Sebastian Greschner wrote:
Hi,
I am having some trouble with the dmrg-program (e.g. of current ALPS 2.0b3) and "complex-valued" models. It seems to me that dmrg ignores the imaginary part of model-parameters (even with COMPLEX set to true). "sparsediag" gives the correct results.
Is this a bug or a general restriction of the dmrg-program? Or is it just a problem of my model or my local installation?
Thanks in advance and greetings, Sebastian
Hi Sebastian,
I fixed one bug and the fix will show up in the MacOS and source versions of thennext nightly snapshot (Friday morning). Can you please try that?
Matthias
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