Re: Data::Table - empty values

One possible solution would be to make sure you check that the cell value is in fact numeric (or an integer as shown below) before you use in a calculation:

$ perl
use strict;
use warnings;
use Data::Table;

my $t = new Data::Table([ [ 1, 2, 3 ], [ 10, 20, " " ] ], [ 'A', 'B' ]
+, 1);

# create emtpy column
my @newCol = ();
$newCol[ $t->nofRow - 1 ] = undef;
$t->addCol(\@newCol, 'adding_up');

# Put the formula in the empty column
$t->colsMap(
  sub {
    $_->[2] =
      ((defined($_->[0]) && $_->[0] =~ m/^\d+$/) ? $_->[0] : 0) +
      ((defined($_->[1]) && $_->[1] =~ m/^\d+$/) ? $_->[1] : 0);
  }
);
print $t->csv;

__END__
A,B,adding_up
1,10,11
2,20,22
3, ,3
[download]

--
Andreas

Comment on Re: Data::Table - empty values - avoid warnings Download Code

Replies are listed 'Best First'.
Re^2: Data::Table - empty values - avoid warnings by andreas1234567 (Vicar) on Oct 25, 2007 at 07:39 UTC
`((defined($_->[0]) && $_->[0] =~ m/^\d+$/) ? $_->[0] : 0)` [download] Am I correct if I assume that here $_ is defined as 'one single digit or maybe a few digits (d+, no spaces and stuff like that in between the digits) and then if this is not the case it should be a 0 (zero)? Almost. It means that `$_->[0]` is defined, and one or more digits 0-9 I would have made it a function to make it more readable: $ perl use strict; use warnings; use Data::Table; my $t = new Data::Table([ [ 1, 2, 3 ], [ 10, 20, " " ] ], [ 'A', 'B' ] +, 1); # create emtpy column my @newCol = (); $newCol[ $t->nofRow - 1 ] = undef; $t->addCol(\@newCol, 'adding_up'); # Return input if input is an integer, otherwise zero sub to_int_or_zero { my $value = shift; if (defined($value) && $value =~ m/^\d+$/) { return $value; } else { return 0; } } # Put the formula in the empty column $t->colsMap( sub { $_->[2] = to_int_or_zero($_->[0]) + to_int_or_zero($_->[1]); } ); print $t->csv; __END__ A,B,adding_up 1,10,11 2,20,22 3, ,3 [download] -- Andreas	[reply] [d/l] [select]
Re^3: Data::Table - empty values - avoid warnings by GertMT (Hermit) on Oct 25, 2007 at 16:14 UTC
okay thanks a lot. I'm almost there but found out that actually the columns I'm working on have a lot of numbers that have as a decimal separator a 'comma'. For example in the blank spot number like 2,3 as opposed to the 'space'. To work around that I thought to do `sub to_int_or_zero { my $value = shift; $value =~ s/,/\./; if (defined($value) && $value =~ m/^\d+$/) { return $value; } else { return 0; } }` [download] but it doesn't work. The 2,3 nicely changes into 2.3 but I'm obviously making a very elementary mistake that I can't understand myself at this moment as the row adds up to ... 3 : (	[reply] [d/l]
Re^4: Data::Table - empty values - avoid warnings by eric256 (Parson) on Oct 25, 2007 at 16:39 UTC
If you check How do I determine whether a scalar is a number/whole/integer/float? you'll see that there are several different regex to choose from depending on what types of numbers you want to allow. ___________ Eric Hodges	[reply]
Re^5: Data::Table - empty values - avoid warnings by GertMT (Hermit) on Oct 25, 2007 at 18:01 UTC
Re^6: Data::Table - empty values - avoid warnings by GertMT (Hermit) on Oct 25, 2007 at 18:53 UTC
Re^2: Data::Table - empty values - avoid warnings by GertMT (Hermit) on Oct 24, 2007 at 20:23 UTC
thanks for your reply. I'm a bit puzzled with the regex. `((defined($_->[0]) && $_->[0] =~ m/^\d+$/) ? $_->[0] : 0)` [download] Am I correct if I assume that here $_ is defined as 'one single digit or maybe a few digits (d+, no spaces and stuff like that in between the digits) and then if this is not the case it should be a 0 (zero)? Never used this ternary operator and just want to make sure that's what it is. thanks	[reply] [d/l]
Re^3: Data::Table - empty values - avoid warnings by Anonymous Monk on Oct 25, 2007 at 05:31 UTC
Am I correct if I assume that here $_ is defined as 'one single digit or maybe a few digits ... No, `$_` is array reference not a scalar. `$_` is not being tested for simple number-ness, but the deferenced value, `$_->[0]`, is. Other than that, you are correct in your reading about which value is eventually going to be added. - parv	[reply] [d/l] [select]
Re^4: Data::Table - empty values - avoid warnings by Anonymous Monk on Oct 25, 2007 at 05:39 UTC
Oh, but a array reference is a scalar, if only a special type of it. No, $_ is array reference not a scalar. That was rather thoughtless of me. First sentence should have been: "No, `$_` is array reference (not a simple value)." -parv	[reply] [d/l]