[R] Error: unexpected string constant

[Gavin Simpson]

On Fri, 2011-01-07 at 12:17 -0800, paogeomat wrote:
> I want to analize some points location using the ppp, but i have this
> problem:
> 
> Datos=read.table("puntos_texto.txt",dec=".",sep="\t",header=T)
> > summary(Datos)
>        id               y                 x          
>  Min.   :   1.0   Min.   :1013581   Min.   :1177842  
>  1st Qu.: 821.2   1st Qu.:1014442   1st Qu.:1179658  
>  Median :1641.5   Median :1014455   Median :1179670  
>  Mean   :1641.8   Mean   :1014465   Mean   :1179652  
>  3rd Qu.:2462.8   3rd Qu.:1014473   3rd Qu.:1179680  
>  Max.   :3283.0   Max.   :1015575   Max.   :1180213  
> > danta=ppp(Datos$x,Datos$y,c(min(Datos$x)1177842,max(Datos$x)1180213),c(min(Datos$y)1013581,max(Datos$y)1015575))
> Error: inesperado constante numérica en
> "danta=ppp(Datos$x,Datos$y,c(min(Datos$x)1177842"
> > danta=ppp(Datos$x,Datos$y,c(min(Datos$x)"1177842",max(Datos$x)"1180213"),c(min(Datos$y)"1013581",max(Datos$y)"1015575"))
> Error: inesperado string constante en
> "danta=ppp(Datos$x,Datos$y,c(min(Datos$x)"1177842""
> 

Space you code out! The it is easy to spot what is wrong:

danta = ppp(Datos$x, Datos$y, c(min(Datos$x)1177842, max(Datos
$x)1180213), c(min(Datos$y)1013581, max(Datos$y)1015575))

You have lots of the following:

c(min(Datos$y)1013581, max(Datos$y)1015575)
             ^^^                  ^^^

you can't do this! Why are you including the numbers here? These are the
min and max values, so either use c(1177842, 1180213), or c(min(x),
max(x)), or range(x), but not a combination of the numbers and the
function output. Wouldn't this:

c(min(Datos$y), max(Datos$y))

or even

range(Datos$y)

be better?

Also, if we drop the syntax errors for the numbers you keep typing in,
you could write this more cleanly by using `with()`:

danta <- with(Datos, ppp(x, y, c(min(x), max(x)), c(min(y), max(y))))

or using range

danta <- with(Datos, ppp(x, y, range(x), range(y)))

Those two are far easier to read than your code.

HTH

G

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