http://www.k-wave.org/forum/topic/confusion-about-neper2db-and-db2neper-functions Support for the k-Wave MATLAB toolbox en-US Wed, 13 May 2026 17:23:35 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/confusion-about-neper2db-and-db2neper-functions#post-6275 Sun, 04 Feb 2018 10:22:41 +0000 Bradley Treeby 6275@http://www.k-wave.org/forum/ <p>We need to convert from dB/(MHz^y cm) to Nepers/((rad/s)^y m):<br /> - To convert from dB to Nepers, divide by 20 * log10(exp(1)) (approximately 8.7)<br /> - To convert from per cm to per m, multiply by 100<br /> - To convert from per MHz^y to per (rad/s)^y, multiply by (1e-6 / (2*pi)).^y<br /> This gives the formula in the function <code>dB2neper</code>. </p> http://www.k-wave.org/forum/topic/confusion-about-neper2db-and-db2neper-functions#post-6274 Fri, 02 Feb 2018 22:10:28 +0000 caudigi1 6274@http://www.k-wave.org/forum/ <p>Hello,<br /> I am not certain about those functions: neper2dB and dB2neper<br /> If we consider dB2neper, I think the function should be:</p> <p>alpha = 100 * alpha .* ((2*pi) / 1e-6).^y .* (20 * log10(exp(1)));</p> <p>Could you double-check for me ?<br /> Thanks in advance for your time. </p>