Dear All, I would like to automate the analysis and plotting of data taken from a grid. Typically I deal with 2 spatial coordinates and a scalar f(x,y), but the spatial grid is not evenly spaced at all and usually given in this form: x y f(x,y) 0.0 0.048979383 2.7659438106975056 0.0 0.044986665 2.603891585041688 0.0023807306 0.04787451 2.715949356768243 0.0 0.040993948 2.469223979694342 0.0023807306 0.043881793 2.5625191444824265 0.004761461 0.046769638 2.6629703119429022 0.0 0.03700123 2.361940994655468 0.0023807306 0.039889075 2.436480700580665 0.004761461 0.04277692 2.517958884562618 0.0071421918 0.045664765 2.606844303834078 0.0 0.060880877 3.470808435449538 0.0 0.05691371 3.1907723461238686 0.0020467786 0.059650626 3.3672237912200016 0.0 0.05294655 2.9558174712065237 0.0020467786 0.055683464 3.1075221272152054 0.004093557 0.05842038 3.268965886866726 0.0020467786 0.051716298 2.8929170062920653 0.004093557 0.054453213 3.029154848759894 0.006140336 0.057190128 3.1754081073235088 0.0 0.02473231 2.138648866573983 0.0 0.020556964 2.092324627395541 I tried the image plot and lattice but unsuccessfully. Now I am reading about the sp package ( http://cran.r-project.org/src/contrib/Descriptions/sp.html ), but I mainly would like a piece of advice about what tools to use and how to read and plot these data (I suppose it must be common e.g. in geography to deal with this kind of problems). Kind Regards Lorenzo
On Fri, 24 Nov 2006, Lorenzo Isella wrote:> Dear All, > I would like to automate the analysis and plotting of data taken from a grid. > Typically I deal with 2 spatial coordinates and a scalar f(x,y), but > the spatial grid is not evenly spaced at all and usually given in this > form: > x y f(x,y) > 0.0 0.048979383 2.7659438106975056 > 0.0 0.044986665 2.603891585041688 > 0.0023807306 0.04787451 2.715949356768243 > 0.0 0.040993948 2.469223979694342 > 0.0023807306 0.043881793 2.5625191444824265 > 0.004761461 0.046769638 2.6629703119429022 > 0.0 0.03700123 2.361940994655468 > 0.0023807306 0.039889075 2.436480700580665 > 0.004761461 0.04277692 2.517958884562618 > 0.0071421918 0.045664765 2.606844303834078 > 0.0 0.060880877 3.470808435449538 > 0.0 0.05691371 3.1907723461238686 > 0.0020467786 0.059650626 3.3672237912200016 > 0.0 0.05294655 2.9558174712065237 > 0.0020467786 0.055683464 3.1075221272152054 > 0.004093557 0.05842038 3.268965886866726 > 0.0020467786 0.051716298 2.8929170062920653 > 0.004093557 0.054453213 3.029154848759894 > 0.006140336 0.057190128 3.1754081073235088 > 0.0 0.02473231 2.138648866573983 > 0.0 0.020556964 2.092324627395541 > > I tried the image plot and lattice but unsuccessfully. Now I am > reading about the sp package ( > http://cran.r-project.org/src/contrib/Descriptions/sp.html ), but I > mainly would like a piece of advice about what tools to use and how to > read and plot these data (I suppose it must be common e.g. in > geography to deal with this kind of problems).Your data are not on a 2D grid, there are (here) 7 unique x values, but 21 unique y values of 21. You can treat the data as a SpatialPointsDataFrame (see note in R News in 2005), but if you want to display them on an actual grid, you will have to interpolate. For more ideas, perhaps try the R-sig-geo mailing list.> Kind Regards > > Lorenzo > > ______________________________________________ > R-help at stat.math.ethz.ch 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. >-- Roger Bivand Economic Geography Section, Department of Economics, Norwegian School of Economics and Business Administration, Helleveien 30, N-5045 Bergen, Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43 e-mail: Roger.Bivand at nhh.no
On 24/11/06, Roger Bivand <Roger.Bivand at nhh.no> wrote:> On Fri, 24 Nov 2006, Lorenzo Isella wrote: > > > Dear All, > > I would like to automate the analysis and plotting of data taken from a grid. > > Typically I deal with 2 spatial coordinates and a scalar f(x,y), but > > the spatial grid is not evenly spaced at all and usually given in this > > form: > > x y f(x,y) > > 0.0 0.048979383 2.7659438106975056 > > 0.0 0.044986665 2.603891585041688 > > 0.0023807306 0.04787451 2.715949356768243 > > 0.0 0.040993948 2.469223979694342 > > 0.0023807306 0.043881793 2.5625191444824265 > > 0.004761461 0.046769638 2.6629703119429022 > > 0.0 0.03700123 2.361940994655468 > > 0.0023807306 0.039889075 2.436480700580665 > > 0.004761461 0.04277692 2.517958884562618 > > 0.0071421918 0.045664765 2.606844303834078 > > 0.0 0.060880877 3.470808435449538 > > 0.0 0.05691371 3.1907723461238686 > > 0.0020467786 0.059650626 3.3672237912200016 > > 0.0 0.05294655 2.9558174712065237 > > 0.0020467786 0.055683464 3.1075221272152054 > > 0.004093557 0.05842038 3.268965886866726 > > 0.0020467786 0.051716298 2.8929170062920653 > > 0.004093557 0.054453213 3.029154848759894 > > 0.006140336 0.057190128 3.1754081073235088 > > 0.0 0.02473231 2.138648866573983 > > 0.0 0.020556964 2.092324627395541 > > > > I tried the image plot and lattice but unsuccessfully. Now I am > > reading about the sp package ( > > http://cran.r-project.org/src/contrib/Descriptions/sp.html ), but I > > mainly would like a piece of advice about what tools to use and how to > > read and plot these data (I suppose it must be common e.g. in > > geography to deal with this kind of problems). > > Your data are not on a 2D grid, there are (here) 7 unique x values, but 21 > unique y values of 21. You can treat the data as a SpatialPointsDataFrame > (see note in R News in 2005), but if you want to display them on an actual > grid, you will have to interpolate. For more ideas, perhaps try the > R-sig-geo mailing list. > > > Kind Regards > > > > Lorenzo > > > > ______________________________________________ > > R-help at stat.math.ethz.ch 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. > > > > -- > Roger Bivand > Economic Geography Section, Department of Economics, Norwegian School of > Economics and Business Administration, Helleveien 30, N-5045 Bergen, > Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43 > e-mail: Roger.Bivand at nhh.no > >Thanks for the advice, but I hope I have not been misleading: only part of the grid coordinates are reported here (the whole list is very long). Does your conclusion hold anyway? Cheers Lorenzo