pseudocode for getting data from table

Hello monks, do we evaluate pseudocode for certain problem here? if yes i have written a pseudocode and i will post it here so that you guys can evaluate if it is a right way for pseudocoding or not?

[GrandFather]

We have a fairly narrow Perl focus here, but can cope with related topics. If something isn't really a Perl question (like: "How do I choose a web host") it is generally accepted if marked [OT] (Off Topic).

That said, if you are putting together some pseudo code to figure out how you might write a Perl script then I think that is entirely within the usual remit of the site - go for it!

[shabird]

Thank you so much for supporting so basically i am writing a pseudocode for the following problem Given a table as shown in the example below, print out the gene ID as well as the expression level for the gene, if the expression level is >= 100. The pseudo code must be generic, so that it can be used on another, but similar, matrix.

Type                     Gene ID   Organism               Expression l
+evel
Transcription factor     Q0V7X4    Arabidopsis thaliana      58
Transcription factor     P52655    Homo sapiens              2107
Protein kinase           P42753    Arabidopsis thaliana      11
Protein kinase           Q8ND76    Homo sapiens              987765

Here is the pseudocode that i have written to acheive this task please have a look if i write the pseudocode correctly or does it need editing?

table <- INPUT TABLE
WHILE line IN table
    IF line >= 100
        expressionLevel <-  line
            PRINT geneID IN table
            PRINT expression level

[Tux]

That is under-specified. What is the table layout? Spaces only or tabs? With TAB's, have a loog at Text::CSV and it's faster parent Text::CSV_XS. If spaces only, you have a problem, as the first line is not aligned with the rest. If it were, pack/unpack would most likely be of help:

# Example using split on multiple spaces
open my $fh, "<", "INPUT";
while (<$fh>) {
    $. < 100 and next;
    chomp;
    my ($typ, $gid, $org, $lvl) = split m/\s\s+/ => $_;
    say "$. $gid, $lvl";
    }
close $fh;

# Example with TAB's
use Text::CSV_XS;
open my $fh, "<", "INPUT";
my $csv = Text::CSV_XS->new ({ binary => 1, sep_char => "\t", auto_dia
+g => 1 });
while (my $line = $csv->getline ($fh)) {
    $csv->record_number < 100 and next;
    my ($typ, $gid, $org, $lvl) = @{$line};
    say "$. $gid, $lvl";
    }
close $fh;

# Example with unpack (I manually aligned the header line)
open my $fh, "<", "INPUT";
while (<$fh>) {
    $. < 100 and next;
    chomp;
    my ($typ, $gid, $org, $lvl) = unpack "A25 A10 A26 A*" => $_;
    say "$. $gid, $lvl";
    }
cloase $fh;

[choroba]

I see a problem here:

IF line >= 100

You first need to extract the expression level from the line, then compare it to 100. You can't compare the whole line against 100, as it's a string.

[BillKSmith]

What do you need pseudocode for? If your employer requires it to document program design before you begin code, he probably specifies a grammar and has his own idea about what is sufficient detail. At the other extreme, it can be something that you write on your napkin while enjoying your morning coffee. In the first case, we can only guess what the boss might want. As long as it is for your own use, you are the best one to decide when it is done. It is done when you believe that the work required to improve it is greater than the work it will save you later.

I often use Perl itself as pseudocode. I call subroutines which do not exist yet, omit initialization and formats, make my best guess at syntax that I am not sure of, etc. Then I compile it and fix the syntax errors. Then I add details until I have a working program.

[GrandFather]

Like BillKSmith I tend to go straight to sketch code rather than something that looks a little like code but doesn't morph directly into anything in particular. That gives me a head start in writing the actual code and also helps me think about testing.

So for your sample I might write something like:

use strict;
use warnings;

my @tableLines = FetchTable();

for my $tableLine (@tableLines) {
    next if $tableLine->{expressionLevel} >= 100;
    
    print "TableLine->{geneID} TableLine->{expressionLevel}\n";
}

which is at least as good as the pseudo code at elaborating the idea for the program, is insignificantly harder to set down, and focuses attention on important elements of the program that are unclear in the pseudo code (what does PRINT geneID IN table really mean?). In the real world these days tools like pseudo code and flow diagrams (for code) are seldom used and are of limited utility compared to things like test driven development.

If this is a homework exercise it may still be worth sketching the program as I have done above and then "reverse engineer" the pseudo code from it. If my sketch code captures your intent then the pseduo code you have as it stands is fine.

[perlfan]

Sometimes I hand write pseudocode, but I call it an "algorithm". Then I implement the algorithm in Perl and run/debug/write until it works. I don't focus on optimiziation if it's outside my normal idiomatic domain. I am telling you this because I think it's most efficient for all of us, but you especially you, to come here during the phase where maybe you've run into an issue with your real code. e.g., "I can't get this to work" or "I don't know how to do this part", etc.

Back to your question. What "table" do you mean? database, html, excel, csv? In all of those cases there is a Perl module on CPAN that will help you. In the case of it being your kitchen table, some monks know a little about wood working as well xD