http://www.k-wave.org/forum/topic/the-negative-pressures-in-homogeneous-propagation-medium-example Support for the k-Wave MATLAB toolbox en-US Wed, 13 May 2026 04:33:55 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/the-negative-pressures-in-homogeneous-propagation-medium-example#post-7805 Fri, 11 Sep 2020 10:02:09 +0000 Bradley Treeby 7805@http://www.k-wave.org/forum/ <p>Hi Remy,</p> <p>In 1D, i.e., if you have a plane wave, the field will remain positive if the source is positive. In higher dimensions, the signal is related to the derivative of the source, and thus negative parts are produced. There is a series of papers by <a href="https://scholar.google.co.uk/citations?user=w1mSLbwAAAAJ&amp;hl=en&amp;oi=sra">Gerald Diebold</a> that explains this nicely.</p> <p>Brad </p> http://www.k-wave.org/forum/topic/the-negative-pressures-in-homogeneous-propagation-medium-example#post-7783 Mon, 31 Aug 2020 03:02:58 +0000 sins 7783@http://www.k-wave.org/forum/ <p>Hi,<br /> Thank you for this useful tool for Photoacoustic Tomography. I was a new student in this field. I was thinking about the negative pressures of the first example 'Homogeneous Propagation Medium Example'. I'm confused about the computing results of the negative pressures when the initial pressure distributions are all positive. How do the negative pressures produce? I think it should be all positive when the initial pressures are all positive.<br /> Thank you for your help.</p> <p>Remy. </p>