One approach would be to smooth the data using `gam' from package `mgcv'. `vis.gam' will contour the resulting smoothed fit if you select `plot.type="contour"'. If the results look ok but you want finer control of what the plot looks like then `predict.gam' can be used to predict from the fitted smooth on any regular grid suitable for supplying to `contour' (although you have to supply the grid!).
On Wednesday 01 October 2008 13:05, Mark wrote: > Please help me to produce smoothed contour plots. > > I have dependent data generated at regular intervals of two independent > variables and would like to produce smoothed contour plots - I cannot get > interp (alima) to produce cubic interpolations of the data, only linear > ones. I'm interested in smoothing as the data generation process is > stochastic and produces small variations which I'd rather 'smooth' away. I > cannot spot what is different about my data from the examples in (akima) > which prevents this working. > > here is an example of my data: > > x > > 0 50 100 150 200 250 300 350 400 450 500 0 50 100 150 200 250 300 > 350 400 > [21] 450 500 0 50 100 150 200 250 300 350 400 450 500 0 50 100 150 > 200 250 300 > [41] 350 400 450 500 0 50 100 150 200 250 300 350 400 450 500 0 50 > 100 150 200 > [61] 250 300 350 400 450 500 0 50 100 150 200 250 300 350 400 450 500 > 0 50 100 > [81] 150 200 250 300 350 400 450 500 0 50 100 150 200 250 300 350 400 > 450 500 0 > [101] 50 100 150 200 250 300 350 400 450 500 0 50 100 150 200 250 300 > 350 400 450 > [121] 500 > > > y > > [1] 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.05 0.05 0.05 > 0.05 0.05 > [17] 0.05 0.05 0.05 0.05 0.05 0.05 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 > 0.10 0.10 > [33] 0.10 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.20 0.20 > 0.20 0.20 > [49] 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.25 0.25 0.25 0.25 0.25 0.25 0.25 > 0.25 0.25 > [65] 0.25 0.25 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.35 > 0.35 0.35 > [81] 0.35 0.35 0.35 0.35 0.35 0.35 0.35 0.35 0.40 0.40 0.40 0.40 0.40 0.40 > 0.40 0.40 > [97] 0.40 0.40 0.40 0.45 0.45 0.45 0.45 0.45 0.45 0.45 0.45 0.45 0.45 0.45 > 0.50 0.50 > [113] 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 > > > zz > > [1] 105136 98444 95021 79375 72532 64392 57819 44413 40610 26083 > 18077 > [12] 96188 87863 80205 69503 61000 50387 44306 33432 22958 17575 > 10892 > [23] 88402 75263 65109 63717 50998 39837 28576 25960 17531 > 8510 5733 > [34] 70806 59245 53970 46113 38455 30492 23836 17870 10954 > 5218 2266 > [45] 68272 58610 47854 34834 32363 24238 19236 11789 6206 > 2515 2141 > [56] 58448 47706 43001 39592 22840 18264 11564 6292 2915 > 2228 2090 > [67] 55817 47680 38460 31693 21331 13161 8050 3162 2302 > 2120 1990 > [78] 54078 43720 32828 22618 17039 8524 4846 2392 2154 > 2068 2008 > [89] 47459 39734 29525 21325 10602 6406 3525 2207 2062 > 2014 1952 > [100] 47630 34965 28452 18966 8386 5726 2351 2145 2052 > 1999 1960 > [111] 42173 34339 27449 16743 9643 2866 2208 2096 2018 > 1937 1886 > > [[alternative HTML version deleted]] > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html and provide commented, minimal, > self-contained, reproducible code. -- > Simon Wood, Mathematical Sciences, University of Bath, Bath, BA2 7AY UK > +44 1225 386603 www.maths.bath.ac.uk/~sw283 ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
