RMprecip               package:fields               R Documentation

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_D_e_s_c_r_i_p_t_i_o_n:

     'RMprecip' is a useful spatial data set of moderate size
     consisting of 865  locations. See www.image.ucar.edu/Data for the
     source of these data.  'PRISMelevation' and 'RMelevation' are
     gridded elevations for the  continental US and Rocky Mountain
     region at 4km resolution.  Note that the gridded elevations from
     the PRISM data product are different than the exact station
     elevations. (See example below.)

_F_o_r_m_a_t:

     The data set  'RMprecip' is a list containing the following
     components: 


     _x Longitude-latitude position of monitoring stations. Rows names
          are station id codes. 

     _e_l_e_v Station elevation in meters. 

     _y Monthly total precipitation in millimeters. for August 1963


     The data sets  'PRISMelevation' and   'RMelevation' are lists  in
     the usual R grid format for images and contouring

     They have  the following components:

     _x Longitude-latitude grid at approximately 4km resolution

     _e_l_e_v Average  elevation for grid cell in meters


     These elevations and the companion grid formed the basis for the
     103-Year High-Resolution Precipitation Climate Data Set for the
     Conterminous United States <URL:
     ftp://ftp.ncdc.noaa.gov/pub/data/prism100> archived at the
     National Climate Data Center. This work was primarily authored by
     Chris Daly <URL: www.prism.oregonstate.edu> and his PRISM group
     but had some contribution from the Geophysical Statistics Project
     at NCAR.  and is an interpolation of the observational data to a
     4km grid that takes into account topography such as elevation and
     aspect.

_E_x_a_m_p_l_e_s:

     # this data set was created  the 
     # historical data  taken from 
     # Observed monthly precipitation, min and max temperatures for the coterminous US 
     # 1895-1997
     # NCAR_pinfill 
     # see the Geophysical Statistics Project datasets page for the supporting functions 
     # and details. 

     # plot 
     quilt.plot(RMprecip$x, RMprecip$y)
     US( add=TRUE, col=2, lty=2)

     # comparison of station elevations with PRISM gridded values

     data(RMelevation)

     interp.surface( RMelevation, RMprecip$x)-> test.elev

     plot( RMprecip$elev, test.elev, xlab="Station elevation", 
     ylab="Interpolation from PRISM grid")
     abline( 0,1,col="blue")

     # some differences  with high elevations probably due to complex
     # topography!

     #
     # view of Rockies looking from theSoutheast

     save.par<- par(no.readonly=TRUE)

     par( mar=c(0,0,0,0))
     persp( RMelevation, theta=75, phi= 15, 
               box=FALSE, axes=FALSE, xlab="", ylab="", 
              border=NA,
              shade=.95, lphi= 10, ltheta=80,
              col= "wheat4", 
              scale=FALSE, expand=.00025)

     par( save.par)
     image.plot(RMelevation, col=topo.colors(256))
     US( add=TRUE, col="grey", lwd=2)
     title("PRISM elevations (m)")

