Hi Lily: I haven't used it to any extent to give you specifics, but I strongly suggest you look at the package sf, it is designed to do these sorts of things. sf can read in the shapefile, and it has features to covert the dataframe you describe to one of its objects, and to combine objects. There are even plotting functions I believe, or if not there is a ggplot2::geom_sf()
HTH, -Roy > On Sep 13, 2018, at 7:02 PM, lily li <chocol...@gmail.com> wrote: > > Hi Petr, > > I have merged the data using cbind. The dataset is like this: > DF > lat1_lon1 lat1_lon2 lat1_lon3 ... lat2_lon1 > 1.20 1.30 2.11 ... 1.28 > 1.50 1.81 3.12 ... 2.34 > 2.41 2.22 1.56 ... 2.50 > 3.11 4.21 2.12 ... 3.21 > > The other file is a shapfile, which I can open using readOGR. Then it shows > a polygon according to geographical latitude and longitude in degrees. How > to overlay the values in DF onto the polygon? note that DF has the > coordinates for a rectangular box that includes the shapefile, but is > larger. I don't know how to do this. Thanks for your help. > > On Wed, Sep 12, 2018 at 3:22 PM, PIKAL Petr <petr.pi...@precheza.cz> wrote: > >> Hi >> >> 1. Read files/lines into R ?read.table, ?read.lines >> 2. Merge files according to your specification ?merge, ?rbind >> 3. Plot values by suitable command(s) ?plot, ?ggplot >> 4. If you want more specific answer, please post more specific question, >> preferably with concise and clear example. >> 5. Avoid posting in HTML >> >> Cheers >> Petr >> >>> -----Original Message----- >>> From: R-help <r-help-boun...@r-project.org> On Behalf Of lily li >>> Sent: Wednesday, September 12, 2018 8:55 AM >>> To: R mailing list <r-help@r-project.org> >>> Subject: [R] how to plot gridded data >>> >>> Hi R users, >>> >>> I have a question about plotting gridded data. I have the files >> separately, but do >>> not know how to combine them. For example, each txt file has daily >>> precipitation data at a specific grid cell, named pr_lat_lon.txt. How to >> plot all >>> txt files for one surface (which is rectangular in this case), or how to >> combine >>> the txt files together? Thanks. >>> >>> [[alternative HTML version deleted]] >>> >>> ______________________________________________ >>> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >>> 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. >> Osobní údaje: Informace o zpracování a ochraně osobních údajů obchodních >> partnerů PRECHEZA a.s. jsou zveřejněny na: https://www.precheza.cz/ >> zasady-ochrany-osobnich-udaju/ | Information about processing and >> protection of business partner’s personal data are available on website: >> https://www.precheza.cz/en/personal-data-protection-principles/ >> Důvěrnost: Tento e-mail a jakékoliv k němu připojené dokumenty jsou >> důvěrné a podléhají tomuto právně závaznému prohláąení o vyloučení >> odpovědnosti: https://www.precheza.cz/01-dovetek/ | This email and any >> documents attached to it may be confidential and are subject to the legally >> binding disclaimer: https://www.precheza.cz/en/01-disclaimer/ >> >> > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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. ********************** "The contents of this message do not reflect any position of the U.S. Government or NOAA." ********************** Roy Mendelssohn Supervisory Operations Research Analyst NOAA/NMFS Environmental Research Division Southwest Fisheries Science Center ***Note new street address*** 110 McAllister Way Santa Cruz, CA 95060 Phone: (831)-420-3666 Fax: (831) 420-3980 e-mail: roy.mendelss...@noaa.gov www: http://www.pfeg.noaa.gov/ "Old age and treachery will overcome youth and skill." "From those who have been given much, much will be expected" "the arc of the moral universe is long, but it bends toward justice" -MLK Jr. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
