Regarding the Near-field Calculations

Regarding the Near-field Calculations

Pradeep Bhatia (guest) 02 Feb 2018 08:06

Dear Sir
I am doing the near-field calculations, as given in user guide of DDSCAT 7.3 on 29, 29.1 & 29.2 sections. when, we calculate the near-field calculation after choosing important parameter i.e. 1 = NRFLD (=0 to skip nearfield calc., =1 for nearfield E, =2 for E and B) and 2 = IORTH (=1 to do only pol. state e01; =2 to also do orth. pol. state), and 1 = IWRKSC (=0 to suppress, =1 to write ".sca" file for each target orient.; After doing these changing in ddscat.par file and run in the ddscat. we got the extra file like w000r000k000.E1 & w000r000k000.E2 and so on….w000r000k000.E200. Till now, i followed these steps.
Now, my Question is how to use .E2, .E2, .E3 and so on .E200 files for further calculation ?
Q1. Is it single point calculation.
Q2. If it is not single point calculation, then how to add these file into E1+E2…….=En
Q3. is it run directly through ddpostprocess or we have to make ddpostprocess.par file. if yes, then How to make and which parameter are use in ddpostprocess.par file. and how to run after preparing the ddpostprocess.par file.
I wish you will reply soon.
Thanking You

Re: Regarding the Near-field Calculations

draine 05 Feb 2018 21:31

As explained in the UserGuide, wxxxryyykzzz.E1 and wxxxryyykzzz.E2 each contain the electric fields
E_sca and E_inc at each point j in the computational volume, where the total E=E_sca+E_inc,
for incident polarizations 1 and 2.

The files wxxxryyykzzz.En are intended to be read by the program DDPOSTPROCESS.f90.
If you compile and run this on the same architecture that was used to run DDSCAT, DDPOSTPROCESS should be able to read the binary files wxxxryyykzzz.En created by DDSCAT.

Please see section 30 of the UserGuide for instructions on using DDPOSTPROCESS.
The user needs to create a file ddpostprocess.par to tell DDPOSTPROCESS what output is desired.
An example of ddpostprocess.par (as well as output files) can be found in examples_exp/ELLIPSOID_NEARFIELD

Re: Regarding the Near-field Calculations

Bryan Bronson 15 Sep 2022 07:22

Buy  A Valid ✅ Passports ✅ Driver's License ✅ ID Cards ✅ Certificates etc. WhatsApp[phone]

((WhatsApp[phone])) We are premium producers of authentic, high-quality novelty and genuine database registered citizenship/identification documents.
Apply for your full UK driving licence alongside the theory and practical certificates. We offer database-registered documents for the following countries only.
We offer complete packages for the following countries worldwide. Germany, Denmark, Sweden, Latvia, USA, Canada, Australia and Norway. ((WhatsApp[phone]))

OUR QUALITY SERVICES:
All our team is made up of active workers of the Driver and Vehicle Licensing Agency and Driver & Vehicle Agency who have come together for the past 13 years to bring an end to the people's struggle.
The procedure to get a driving licence in the United Kingdom is not different from the other European nation's processes, have time-consuming and expensive. Thus, time-consuming and costly process have a time-consuming and expensive process to go through a driving school for both the written and practical parts.
This is usually a cumbersome process that is time-consuming and also very expensive.
We are a team of highly skilled professionals working directly with several driving schools all over the United Kingdom that helps to facilitate the process for our customers to get their required documents without stress.
From watermarks to the right font, size and style, we know what to do to give you the best realistic-looking certificates or any document you need.
It would help if you were informed that all your information would be available online at gov. UK
You won’t have to worry about substandard work compromising any of your loan applications or if you need to give one over to the company for record-keeping purposes.

ARE THESE PURCHASED DOCUMENTS REGISTERED?

Of course, all documents we provide on this site, regardless of their categories, are registered in the state's databases.
We have produced over 16,212 documents since we started, and none of our clients has ever complained of complications.
The anonymity of our clients is highly respected, which is one of our principal focuses.
Do you have trouble passing the theory or practical test and went with that because we produce all categories of drivers with a Verified Driving License?
We can help you with that because we produce all categories of driver's licenses at a very affordable rate compared to other agencies.
We are premium producers of authentic, high-quality novelty and genuine database registered citizenship/identification documents.
Here we produce original data based on registered documents such as
IELTS certificates
Biometric Passports
Visa
Golden Visa
Driver Licence
Biometric Residence Permit Cards
ID Cards
Birth certificates
All our documents can also be used anywhere, for any purpose, without any problem; almost all our clients are most noteworthy. We are the best in providing original data-based registered documents/certificates.
Without clients writing any exams. It seems like a joke because you can’t believe we can go furthermore to open your opportunities, so try our services now.
Finally, we will produce your documents within 10  to 15 working days. Therefore you can expect your certificate/documents/passports/driving licences, etc., within 10 to 15 working days after your order is placed.
Buy IELTS certificate online | Available IELTS certificate without exam  | Buy Genuine Golden Visa | Genuine Biometric Residence Permit Cards  | Original ID Cards  | Buy actual Visa Stickers  | Original Birth certificates | Get Your Driving Licence (UK) | Buy Your Original Driver's License (EU) Canada |
✅ Passports ✅ Driver's License ✅ ID Cards ✅ Certificates & Lots more.
Contact us today.

HOW IS THE DELIVERY DONE?
The document will be delivered to your home under discrete measures, safe and confidential.
Apply for Passport, Id cards, Driving License, Birth Certificates, Expungement WhatsApp,d [phone]   IELTS, TOEFL Schengen visa.
Clean criminal records.  We clean criminal records for more details contact on us WhatsApp [phone]
We are an Association network responsible for producing genuine passports, Real Genuine Data-Base Registered Passports and other Citizenship documents.
We can guarantee accurate and valid documents worldwide; you can have a new Identity starting from a clean new genuine Birth Certificate, ID card, Drivers License, Passports, Social security card, and credit files, can you imagine?

We are premium producers of authentic, high-quality novelty and genuine database registered citizenship/identification documents.WhatsApp and [phone]
✅ Passports ✅ Driver's License ✅ ID Cards ✅ Certificates & Lots more.
    * Basic Contact Information Bellow *
WhatsApp Number+447537106615
Direct Calls OR Text:[phone]  

Shweta (guest) 05 Jun 2018 15:43

Sir, I am using DDSAT 7.3.2.
In ddpostprocess.par, the line
-0.59684 0.0 0.0 0.59684 0.0 0.0 501 = XA,YA,ZA, XB,YB,ZB (phys units), NAB
gives the electric field along one track.
I want to write electric field along a matrix (i.e. multiple tracks).
Please suggest the modification.

draine 05 Jun 2018 17:15

As explained in section 30.1 of the 7.3.2 UserGuide, each "track" is specified by one line in ddpostprocess.par
In principle, ddpostprocess.par can specify many tracks (one line per track).

If this doesn't address your requirements, then you may need to modify the program ddpostprocess.f90 to create a new version to write out what you want — see section 30.2 of the UserGuide for a few words about this. The critical piece of code is subroutine readnf.f90 (called by ddpostprocess.f90) which reads the stored data file (e.g., 'w000r000k000.E1') from disk, and returns information about the polarization, electric field, etc at each lattice site. You will probably need prior experience with f90 programming if you are going to undertake this route.

It would be nice if some DDSCAT user would write some MATLAB code to do this, and make it available, but so far as I am aware this hasn't happened.

Inconsistent j1 Issue

DrPseudo 29 Aug 2018 16:50

Hello,

I've downloaded the latest DDSCAT 7.3.2 version, compiled it using gfortran/MINGW for windows (windows 10), and run ddscat.exe
This works, however ddpostprocess.exe, which was compiled at the same time as ddscat.exe (so same architecture), always throws the error "readnf sanity failure: inconsistent j1 = 86343 and nat0 = 87601"

readnf is clearly having an issue reading the wxxxryyykzzz.E1 file, and seems to be finding an incorrect number of dipoles in some iterative loop its running to do calculations, as j1 is a variable counting the iterations of a set of loops in readnf.

How would you recommend remedying this problem?
Could my wxxxryyykzzz.E1 file contain NAN values, which get skipped by readnf?

Thanks!

Re: Inconsistent j1 Issue

draine 29 Aug 2018 21:04

1. Have you tried running ddpostprocess on any of the examples? For example, ELLIPSOID_NEARFIELD ? (This works for me).
2. Because of a possible error involving sym links, the previous distribution of ddscat7.3.2 source code might have included an obsolete file. I just uploaded an up-to-date distribution, ddscat7.3.2_180829.tgz to this site.
If you continue to have trouble with ddpostprocess, I suggest going to Donwloads, download ddscat7.3.2_180829.tgz, and then recompile ddscat and ddpostprocess.

Re: Inconsistent j1 Issue

DrPseudo 31 Aug 2018 18:39

Thank you for your reply!
I figured out the problem after looking through a bit of the code for ddpostprocess.f90 and thought I'd share for any future people encountering a similar error - I had accidentally assigned multiple compositions to the same lattice positions, which caused the ICOMP(k,x,y,z) function to return 0 for a few lattice positions and the J1 iterator to miscount the number of dipoles in the target geometry.

Re: Regarding the Near-field Calculations

DrPseudo 31 Aug 2018 18:46

Hello again,

Is there a way for ddpostprocess.exe to take the nearfield calculations from wxxxryyykzzz.E1 and wxxxryyykzzz.E2 at the same time?
I'm looking to plot a contour map of the nearfield for an asymmetric geometry where the polarization direction is important, and I can only seem to plot it for one polarization direction at a time from either .E1 or .E2

Any suggestions?

Re: Regarding the Near-field Calculations

Christina Boukouvala 04 Feb 2021 13:12

Hello,

I am performing near-field calculations of nearly perfect disk shaped nanoparticles however I get NaN values for the field in the interior of the particles. This does not happen for other particles I have tried which had lower symmetry. Do you have a suggestion on what might be causing that and how to work around it?

Thank you!