Bugreport: Tide chart rendering glitch

   Error in graphical rendering of tide chart.  When I scroll time left to right, the white dot with text for time and tide seems to report ok, but the summary text in the upper right is unrealistic, and there is a different graphical error in the chart itself.  ( I could not capture the white dot in a screenshot )  
    I'm using harmonics-dwf-20191229-free.tcd from  flaterco.com/xtide/files.html#harmonicsfiles and this file renders properly in xtide.

    secondarily / other bug : the y axis of tide charts never show the negative parts of the charts.

Hi,
Thanks for the report. I can see the problem with this strange station.

Wondering what a negative water level is meaning, can you explain ?

-- Philippe

The zero line an abstract idea, more precisely it is 'mean lower low water.' There is no particular geographic location at which this zero line is defined. It is a statistical convenience, a created point of reference. In the second photo I attatched above, the xtide graph in the middle of the screenshot shows our local tides crossing the zero line several times and nothing special happening. Here is a bookmark to a big USA NOAA glossary tidesandcurrents.noaa.gov/glossary.html .

I think the station data in this case is good, nothing special, and there is some quirky rendering error in the qtVlm graphical rendering, like a untrapped divide by zero error or something.

thanks Stewart
Je ne pe pas ecrit le Fransais excuses moi

OK, I have made some changes to accommodate this. If you are running qtVlm on Windows it is easy to send you a patched version to test.

I run it on Android 11 and Debian buster. I could install it on my rarely used windows partition to test it.

I see several older versions of vlm & qtVlm on github: is qtVlm not open source now?

No qtVlm is not open souce
There is a pre release of p1 available here can you please check the tide issue is fixed ?
www.virtual-winds.org/maitai/qtVlm-5.10.3-64_1-patch1.tar.gz