[R] colors, lines, characters .... documentation

[Henrik Bengtsson]

Hi, many questions at once there, but here some help regarding
*symbols*. 

I've pasted a function plotSymbols() that shows all symbols available.
Note that the the symbols pch >= 128 are system dependent so you
should not expect them to look the same on Windows, Mac and Unix. Try
also plotSymbols(TRUE). To turn of the click-bell do
'options(locatorBell=FALSE)' (see ?locator).

Cheers

Henrik

----------------------------------------------------
BEGIN code
----------------------------------------------------
plotSymbols <- function(interactive=FALSE) {
  ASCII <- c("\000", sapply(1:255, function(i)
parse(text=paste("\"\\",
                    structure(i,class="octmode"), "\"",
sep=""))[[1]]));

  intToChar <- function(i) {
    ASCII[i %% 256 + 1];
  }

  interactive <- interactive && interactive();

  i <- 0:255;
  ncol <-16;
  
  top <- 3 + 2*interactive;
  opar <- par(cex.axis=0.7, mar=c(3,3,top,3)+0.1)
  on.exit(par(opar))

  plot(i%%ncol,1+i%/%ncol, pch=i, xlim=c(0,ncol-1), xlab="", ylab="", 
 
axes=FALSE);
  axis(1, at=0:15)
  axis(2, at=1:16, labels=0:15*16, las=2)
  axis(3, at=0:15)
  axis(4, at=1:16, labels=0:15*16+15, las=2)
  if (interactive) {
    title(main="Click on a symbol to add it to the data frame. Click
in margin to quit!", cex.main=0.8, line=3.5);
  }

  if (interactive) {
    df <- list();
    usr <- par("usr");
    ready <- FALSE;
    while (!ready) {
      click <- locator(n=1);
      x <- click$x;
      y <- click$y - 1;
      ready <- !(x > 0.5 && x < 15.5 && y > 0.5 && y < 15.5);
      if (!ready) {
        x <- round(x);
        y <- round(y);
        z <- 16*y + x;
        ch  <- intToChar(z);
        dec <- as.character(z); 
        hex <- intToHex(z);
        oct <- intToOct(z);
        spc <- paste(rep("0", 2-nchar(hex)), collapse="");
        hex <- paste(spc, hex, sep="");
        spc <- paste(rep("0", 3-nchar(oct)), collapse="");
        oct <- paste(spc, oct, sep="");
        df$ch  <- c(df$ch , ch );
        df$dec <- c(df$dec, dec);
        df$hex <- c(df$hex, hex);
        df$oct <- c(df$oct, oct);

        if (nchar(ch) == 0) ch <- " ";
        spc <- paste(rep(" ", 3-nchar(dec)), collapse="");
        dec <- paste(spc, dec, sep="");
        cat("Selected ASCII character '", ch, "' ", dec, " 0x", hex, 
                                                 " \\", oct, "\n",
sep="");
      }
    }
    return(df);
  }

  invisible()
} # plotSymbols()
----------------------------------------------------
END code
----------------------------------------------------

> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch 
> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Monica 
> Palaseanu-Lovejoy
> Sent: den 24 mars 2004 16:06
> To: r-help at stat.math.ethz.ch
> Subject: [R] colors, lines, characters .... documentation
> 
> 
> Hi,
> 
> Very so often when i am plotting something, doing a histogram, or 
> whatever i am struggling to find out which are the numbers for 
> different colors, palette names, types of lines, symbols, etc. Is 
> there any documentation on line with all these numbers / names 
> and the associated symbol / color???
> 
> For example if i am using the command image it uses a palette 
> from red to yellow, with red the lowest value, and yellow the
highest 
> value. What if i want a reverse palette, with green the lowest value

> and yellow middle values and red highest value??? Or much more 
> simple, just yellow lowest value and red highest value???
> 
> Thank you for assistance,
> 
> Monica
> 
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> R-help at stat.math.ethz.ch mailing list 
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