http://www.k-wave.org/forum/topic/simulating-data-in-polar-coordinates Support for the k-Wave MATLAB toolbox en-US Wed, 13 May 2026 06:04:09 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/simulating-data-in-polar-coordinates#post-7794 Wed, 09 Sep 2020 19:17:58 +0000 Bradley Treeby 7794@http://www.k-wave.org/forum/ <p>Hi Thomas,</p> <p>Except for when using the axisymmetric code, you're right that the computational grid is always on a regularly-spaced Cartesian grid. This allows us to use the FFT to compute spatial gradients.</p> <p>If you use the new <a href="http://www.k-wave.org/forum/topic/alpha-version-of-kwavearray-off-grid-sources">kWaveArray</a> class, you can place sources and sensors anywhere in the grid without staircasing artefacts (e.g., without the source shape being rastered to the grid). So there shouldn't be any limitations of using a Cartesian grid per se.</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/simulating-data-in-polar-coordinates#post-7761 Fri, 21 Aug 2020 17:33:09 +0000 Thomas2100 7761@http://www.k-wave.org/forum/ <p>Hi </p> <p>I would like to know if it possible to generate data on a polar grid? I would like to generate point sources arranged in a circle and rotate a transducer element to scan the sources as they propagate inwards . However I found that N grid is always set in Cartesian coordinates with equidistant pixel size. Whereas in polar coordinates one would expect the pixel size to increase as a function of depth... </p> <p>I found the ultrasound B scan mode example where a steering angle is used to generate a ultrasound B mode scan but it seems the steering angle is performed on a Cartesian grid rather than cylindrical? is this correct?</p> <p><a href="http://www.k-wave.org/documentation/example_us_bmode_phased_array.php" rel="nofollow">http://www.k-wave.org/documentation/example_us_bmode_phased_array.php</a> </p> <p>Thomas </p>