[Jprogramming] file read

[kamakura]

Hi

I would like to know J's manipulation for reading text file.

fd=:'mytestfile.txt' NB. TAB text file
NB. a \t 1 \t 2 \t 3
NB. b \t \t 5 \t 6
NB. c \t 7 \t \t 9
NB. d \t 10 \t 11 \t 12
NB. \t 13 \t 14 \t 15

fd2=:'mytestfile.csv' NB. CSV test file

load'files misc'
   freads fd2
a,1,2,3
b,,5,6
c,7,,9
d,10,11,12
,13,14,15


   freadr fd ;0 1
a	1	2	3

   freadr fd ;1 1
b		5	6

   freadr fd ;2 1
	7		9
d
   freadr fd ;3 1
10	11	1
   freadr fd ;4 1

	13	14

The 3rd and 4th rows are read differently.  I expect that the following line will come out.

   freadr fd ;2 1
c	7		9



   u=:'m' fread fd
   u
a	1	2	3   
b		5	6    
c	7		9    
d	10	11	12
	13	14	15 

   TAB chop "1 u
+--+--+-----+----+
|a |1 |2    |3   |
+--+--+-----+----+
|b |5 |6    |    |
+--+--+-----+----+
|c |7 |     |9   |
+--+--+-----+----+
|d |10|11   |12  |
+--+--+-----+----+
|13|14|15   |    |
+--+--+-----+----+


How can I get the following table?

+--+--+-----+----+
|a |1 |2    |3   |
+--+--+-----+----+
|b |NA|5    |6   |
+--+--+-----+----+
|c |7 |9    |NA  |
+--+--+-----+----+
|d |10|11   |12  |
+--+--+-----+----+
|NA|13|14   |15  |
+--+--+-----+----+

R reads this text file as follows:

> u=read.table("mytestfile.txt",header=F,na.strings="",sep="\t")
> u
    V1 V2 V3 V4
1    a  1  2  3
2    b NA  5  6
3    c  7 NA  9
4    d 10 11 12
5 <NA> 13 14 15

Do you have any convenient utility function for reading text files?



+++++++++++++++++++++++++++++
    Toshinari Kamakura

    Chuo University
    1-13-27 Kasuga
    Bunkyo-ku
    Tokyo 112-8551, Japan
++++++++++++++++++++++++++++++