[R] OK - I got the data - now what? :-)

[Mark Knecht]

On Sat, Jul 4, 2009 at 5:22 PM, jim holtman<jholtman at gmail.com> wrote:
> See if this example helps; show how to either plot the row or columns
> of a data frame:
>
>> test <- data.frame(C1=runif(10), C2=runif(10), C3=runif(10))
>> test
>           C1        C2        C3
> 1  0.91287592 0.3390729 0.4346595
> 2  0.29360337 0.8394404 0.7125147
> 3  0.45906573 0.3466835 0.3999944
> 4  0.33239467 0.3337749 0.3253522
> 5  0.65087047 0.4763512 0.7570871
> 6  0.25801678 0.8921983 0.2026923
> 7  0.47854525 0.8643395 0.7111212
> 8  0.76631067 0.3899895 0.1216919
> 9  0.08424691 0.7773207 0.2454885
> 10 0.87532133 0.9606180 0.1433044
>> # this will plot each column (C1, C2, C3)
>> matplot(test, type='o')
>> # plot each row
>> matplot(t(test), type='o')
>
>
> On Sat, Jul 4, 2009 at 8:02 PM, Mark Knecht<markknecht at gmail.com> wrote:
>> OK, I guess I'm getting better at the data part of R. I wrote a
>> program outside of R this morning to dump a bunch of experimental
>> data. It's a sort of ragged array - about 700 rows and 400 columns,
>> but the amount of data in each column varies based on the length of
>> the experiment. The real data ends with a 0 following some non-zero
>> value. It might be as short as 5 to 10 columns or as many as 390. The
>> first 9 columns contain some data about when the experiment was run
>> and a few other things I thought I might be interested in later. All
>> the data starts in column 10 and has headers saying C1, C2, C3, C4,
>> etc., up to C390 The first value for every experiment is some value I
>> will normalize and then the values following are above and below the
>> original tracing out the path that the experiment took, ending
>> somewhere to the right but not a fixed number of readings.
>>
>> R reads it in fine and it looks good so far.
>>
>> Now, what I thought I might do with R is plot all 700 rows as
>> individual lines, giving them some color based on info in columns 1-9,
>> but suddenly I'm lost again in plots which I think should be fairly
>> easy. How would I go about creating a plot for even one line, much
>> less all of them? I don't have a row with 1,2,3,4 to us as the X axis
>> values. I could go back and put one in the data but then I don't think
>> that should really be required, or I could go back and make the
>> headers for the whole array 1:400 and then plot from 10:400 but I
>> thought I read that headers cannot start with numbers.
>>
>> Maybe the X axis values for a plot can actually be non-numeric C1, C2,
>> C3, C4, etc and I could use line (C1,0) to (C2,5) and so on? Or maybe
>> I should strip the C from C1 and be left with 1? Maybe the best thing
>> is to copy the data for one line to another data.frame or array and
>> then plot that?
>>
>> Just sort of lost looking at help files. Thanks for any ideas you can
>> send along. Ask questions if I didn't explain my problem well enough.
>> Not looking for anyone to do my work, just trying to get the concepts
>> right
>>
>> Cheers,
>> Mark
>>
>> ______________________________________________
>> R-help at r-project.org 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.
>>
>
>
>
> --
> Jim Holtman
> Cincinnati, OH
> +1 513 646 9390

Hey Jim,
   Thanks for the pointers on matplot. I suspect that will be useful
one of these days.

   I'm attaching a little code to make a test case closer to what I
have to deal with at the bottom. My problem with your data was that
you plot everything. In my data I need to plot only a portion of it,
and in the array not every cell is valid - I don't want to plot cells
that have 0.00 as a value. In the array 'test' I need to plot the
general area defined by C1:C6, each row as a line, but stop plotting
each row when I run into a 0. Keep in mind that I don't know what
column C1 starts in. It is likely to change over time.

   I think the root cause of a number of my coding problems in R right
now is my lack of skills in reading and grabbing portions of the data
out of arrays. I'm new at this. (And not a programmer) I need to find
some good examples to read and test on that subject. If I could locate
which column was called C1, then read row 3 from C1 up to the last
value before a 0, I'd have proper data to plot for one line. Repeat as
necessary through the array and I get all the lines. Doing the lines
one at a time should allow me the opportunity to apply color or not
plot based on values in the first few columns.

Thanks,
Mark

test <- data.frame(A=1:10, B=100, C1=runif(10), C2=runif(10),
C3=runif(10), C4=runif(10), C5=runif(10), C6=runif(10))
test<-round(test,2)

#Make array ragged
test$C3[2]<-0;test$C4[2]<-0;test$C5[2]<-0;test$C6[2]<-0
test$C4[3]<-0;test$C5[3]<-0;test$C6[3]<-0
test$C6[7]<-0
test$C4[8]<-0;test$C5[8]<-0;test$C6[8]<-0

#Print array
test