How to read .shd files from Bellhopcxx2d in MATLAB?

[Roblol99]

Hello,

I am using Bellhop (bellhopcxx2d.exe) to generate .shd files. I want to read these files in MATLAB using the classic ReadShadeBin.m script, but it does not work—the file format seems different from the original Fortran Bellhop.

Is there a MATLAB or Python reader for the new .shd format? Or is there documentation for the binary format so I can write my own reader?

Thank you!

[oldstylejoe]

Thanks for your interest in bellhopcuda! Could you please check what version of Bellhop you mean by 'classic'? The .shd format was changed in recent versions, and bhc is based on the 2022 version.
The MATLAB scripts in here should work. The main difference are some changes from double to single float types.

I don't know of any good documentation of the .shd format, and we figured it out from the MATLAB scripts.

[Roblol99]

Thank you for your answer I found the scripts you linked very helpful, I can now run the Bellhopcxx2d, and its so much faster than the old one i was using. However, the results are quite different between them and im not sure why, all the inputs should be pretty much the same for both. Do you think you could help me with this? Here is comparing the old to the new calculations: [cid:5ccde3a4-7715-4be4-9582-975752a0a917][cid:6e52fc72-91a7-4880-b673-58935d291dd1] I was, and still am using mostly AcTUP V2.2l from here: Download AcTUP V2.2L software, CMST, marine science - Centre for Marine Science and Technology | Curtin University, Perth, Australia<https://cmst.curtin.edu.au/products/underwater/download/> Download AcTUP V2.2L software - Centre for Marine Science and Technology (CMST)<https://cmst.curtin.edu.au/products/underwater/download/> Download AcTUP V2.2L Software. Do you wish to receive news about the Centre for Marine Science and Technology? cmst.curtin.edu.au

…

________________________________ From: oldstylejoe ***@***.***> Sent: 02 June 2025 23:35 To: A-New-BellHope/bellhopcuda ***@***.***> Cc: Robert Løland ***@***.***>; Author ***@***.***> Subject: Re: [A-New-BellHope/bellhopcuda] How to read .shd files from Bellhopcxx2d in MATLAB? (Issue #47) You don't often get email from ***@***.*** Learn why this is important<https://aka.ms/LearnAboutSenderIdentification> [https://avatars.githubusercontent.com/u/12647233?s=20&v=4]oldstylejoe left a comment (A-New-BellHope/bellhopcuda#47)<#47 (comment)> Thanks for your interest in bellhopcuda! Could you please check what version of Bellhop you mean by 'classic'? The .shd format was changed in recent versions, and bhc is based on the 2022 version. The MATLAB scripts in here<http://oalib.hlsresearch.com/AcousticsToolbox/atWin10_2020_11_4.zip> should work. The main difference are some changes from double to single float types. I don't know of any good documentation of the .shd format, and we figured it out from the MATLAB scripts. — Reply to this email directly, view it on GitHub<#47 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/BSZNCTXHCTLMNIXBDOUHECL3BS7RVAVCNFSM6AAAAAB6M7E4H6VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDSMZSGU4TCOBZGU>. You are receiving this because you authored the thread.Message ID: ***@***.***>

[oldstylejoe]

I can't see the images you posted for some reason.
That code is quite from 2005, and there are definitely differences in the last 20 years. Without seeing the figures I'm not sure what differences you're seeing. If it's not too big, you can also share the bellhop files you're using, e.g., .env files.