Path: csiph.com!fu-berlin.de!uni-berlin.de!news.dfncis.de!not-for-mail From: =?UTF-8?Q?Hans-Bernhard_Br=c3=b6ker?= Newsgroups: comp.graphics.apps.gnuplot Subject: Re: chart disappears when i add xrange / yrange to binary array plot of radio spectrogram data Date: Tue, 1 Mar 2016 20:54:28 +0100 Lines: 45 Message-ID: References: <8bd1c7cb-da40-4d20-a789-4e5c6ebd31a0@googlegroups.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit X-Trace: news.dfncis.de jjmyt2JFS2cKvTId7nQfFQfhhCa6ZB3Itc/Dx1JjehrwPrkyWxnA6UALrX Cancel-Lock: sha1:FYg2fiaelsE2t5QGY13IBZuznrQ= User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 In-Reply-To: <8bd1c7cb-da40-4d20-a789-4e5c6ebd31a0@googlegroups.com> Xref: csiph.com comp.graphics.apps.gnuplot:3246 Am 01.03.2016 um 14:58 schrieb Mario Cannistrà: > For the same reason I'm storing only z values > and NO x,y (timestamps, frequencies). I suspect that's your problem right there. Without the time stamps in the data, where are the x coordinates you want to limit the range to supposed to come from? > When I try to uncomment the xrange and yrange statements, i get the > axis labels correctly represented but the data area of the plot > simply disappears. That would be case, as-is, your data file does not actually hold any data inside the ranges you specified. > Please see > https://www.dropbox.com/s/n022h60lyvf57t1/plot-showing-spectrogram.png?dl=0 > for the plot with data and If you take a good hard look at that, you may notice that the x axis is from timestamps 01:06:00 to about 01:07:18, on some unknown day. That doesn't overlap with the range you pass to gnuplot: > gnuplot -e "scanstart='160228082733'" -e "scanend='160228082833'" [...] > rangeonx = '["'.scanstart.'":"'.scanend.'"]' [...] > set format x "%H:%M:%S" > set xrange @rangeonx There are no data around 08:28 h in that file. There is nothing in that plot script that would move the actual (implicit) data range of [0:7999] into the realm of time stamps you specify as your xrange. Binary data in %float format wouldn't be able to hold the kind of resolution you're attempting, anyway: you're specifying a range of 60 seconds, 16 years away from gnuplot's epoch of 2000-01-01. 60 seconds / 16 years only about twice as large as FLT_EPS, i.e. there are only three different single-precision %float numbers in that entire x range.