Brent, Thanks a lot for the reply!
That's a lot of valuable information packed in a few paragraphs! There are a few points I didn't fully understand yet, I hope you don't mind me asking a few more questions: surface, triangulate, xyz2grd, greenspline can all generate a grid from > scattered point data, depending just how you want it done I'm really just beginning with GIS visualizations. If I can get something close to what I've shown in the first message: 1) This http://i.stack.imgur.com/DvVyU.png (with outer edges clipped to the radius contours); 2) Or this https://www.dropbox.com/s/9ig76n1kcxoo76w/Screenshot%202015-07-24%2021.39.00.png?dl=0 ; 3) Or http://www.gislounge.com/wp-content/uploads/2014/08/fortune1000-heat-kernel-us.png . ..I'll be happy. The high-level question I have now is: What would be the minimum set of tools, settings andI need to create a viz. like this from a set of point with a lat, lon and weight value? (value-based, based off the weight and another one based off the density of points) ... specific questions follow: gridhisteq can normalise it if required What do you mean by normalise? When would be this needed? grdimage will turn it into a postscript image Why postscript? ps2raster will turn it into a georeferenced png Interesting, why is this needed specifically? For WMS? if you want to clip it to a contour, you can use psclip, or you can use a > colour palette to set cells >representing certain values to NA, & render > them as transparent Perfect! Yes, I want to the outer edges to follow a organic 'flow', and not crop like the example I sent. Thanks for pointing me out to psclip. Do you know/Could point me to an example/tutorial of how to use it / or the colour palette technique to get the viz. I'd like? Thanks again, -- Marcelo. On Sat, Jul 25, 2015 at 10:47 PM, Brent Wood <[email protected]> wrote: > Generic Mapping Tools (http://gmt.soest.hawaii.edu) can do all you want, > fully scripted: > > surface, triangulate, xyz2grd, greenspline can all generate a grid from > scattered point data, depending just how you want it done > gridhisteq can normalise it if required > grdimage will turn it into a postscript image > ps2raster will turn it into a georeferenced png > > if you want to clip it to a contour, you can use psclip, or you can use a > colour palette to set cells representing certain values to NA, & render > them as transparent > > you can then provide it as a WMS layer with mapserver, qgis server or > geoserver > > See sections 7.14-7.19 here: > http://gmt.soest.hawaii.edu/gmt4/gmt/html/GMT_Docs.html > > GDAL may be adequate, but has a more limited set of gridding & > cartographic tools, and GRASS can also do what you want. > > ------------------------------ > *From:* Marcelo de Moraes Serpa <[email protected]> > *To:* qgis-user <[email protected]> > *Sent:* Saturday, July 25, 2015 3:13 PM > *Subject:* Re: [Qgis-user] Organic heatmap outter contour, and making it > look better > > Ops, forgot to include the reference heatmaps here. The goal is to get it > to look +- like the ones below: > > * > http://www.gislounge.com/wp-content/uploads/2014/08/fortune1000-heat-kernel-us.png > and/or > * http://i.stack.imgur.com/DvVyU.png > > Cheers, > > -- Marcleo. > > > > On Fri, Jul 24, 2015 at 9:58 PM, Marcelo de Moraes Serpa < > [email protected]> wrote: > > Thanks to @Neumann, @Abdishakur and @Richard from my previous thread, the > info was valuable! I did reply the post with some additional questions it > but for some reason the mailing list server bounced my messages. They are > not so relevant anymore, but if you get them, I'd still want to know your > opinions. > > Anyway, I played a couple of hours today with the data I have and with the > interpolation and countours features of QGis (which seems to use Gdal under > the cover, which was, for me, a quite interesting finding! That means that > any result I get with QGis could easily be scriptable, which is a must, > since it will eventually be used in a web app pipeline) and I got this: > > > https://www.dropbox.com/s/9ig76n1kcxoo76w/Screenshot%202015-07-24%2021.39.00.png?dl=0 > > It still doesn't look quite like I want*[0] but I'm getting there. The > countours feature seems to be what I want. The numbers, by the way, is > revenue per day in a certain area. The colors are not quite right (too many > of them) so I need to tweak the styles, I think, and I don't want the > actual countours lines to appear. They all seem to be simple problems to > solve, but if you know how to do them, I'd love to know! > > What seems to be more complicated, is how to create an organic feeling to > the map. I don't want it to be a square, like this, I want the edge to > follow the outter points. Here's what I mean: > https://www.dropbox.com/s/k6na766a4ox1ngg/Screenshot-2015-07-15-21.47.55.jpg?dl=0. > Does anyone have any idea of to do this? > > Thanks! > > -- Marcelo. > > > > > _______________________________________________ > Qgis-user mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/qgis-user > > >
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