So, I think that I understand your requirements - see below. The graph is turned 90 deg to the right from what would be "normal". The width on the page is fixed at 101 characters so we don't have to worry about screen size - I think that is fine even with Windows defaults. I didn't worry about minimizing Plot memory - probably makes no difference at all.

Added: I used a 2-D array for the input data points. The actual Plot itself is a 1D array with a string which represents all possible values of the input data (101 discrete points, 0.0-10.0 in 0.1 increments). substr() is used to manipulate individual characters within the line.

You might want to think some more about perhaps some scaling on the "x" axis (the number of output lines could get quite large). Probably just make some plots with your real data and experiment to find new "requirements".

Note I added the "fill" function for you to play with - can make visualizing things easier to see a solid line instead of a single point. Have fun...

UPDATE: You might want to consider adding the data point to the graph, like this for the first point:
(200,3.5) *******************************
etc. Code to do that left as an exercise.

use strict;
use warnings;
use List::Util qw(min max);

# Simple plotting re: node_id=11146802

use constant MAXLINES => 200;  #Abort if more than 200 lines in printo
+ut

# @inData is the input data to plot
# A 2-D array of pairs (#iterations, value)
#
# Valid #iterations are integers. The graph will take
#    maxiter-miniter+1 lines to display.
#    The zero is suppressed.
# Valid data values are in the range of 0.0-10.0 in 0.1 increments 
#    or rather 101 characters from left of screen to the right
#    indicies [0..100]


my @inData = ([200,3.5],[220,5.8],[210,6.5]);

my @col1 = map{$_->[0]}@inData;    #just extracts col1 as simple array
my $min_iter = min (@col1);    #these funcs are faster than a sort
my $max_iter = max (@col1);

print "minimum iter=$min_iter ; maximum iter= $max_iter\n";

#you decide what you want here...
die "Too many lines required! ABORT!" if ($max_iter-$min_iter+1 > MAXL
+INES);

my @Plot;
#initialize Plot Matrix  
# "burns" some memory at beginning of array to avoid a linear 
#     "offset" adjustment factor
#
$Plot[$_]=" " x 101 for ($min_iter..$max_iter);

foreach my $row_ref (@inData)
{
   my ($n_iter, $data) = @$row_ref;
   plot_point ($n_iter, $data,1);  #can turn FILL OFF if desired
}
dumpPlot();

############

sub plot_point
{
   my ($n_iters, $data, $fill) = @_;
   
   $fill //= 0;   #fill defaults to none
   my $height = get_height($data); # height range 0 - 100
   die "Data Value $data out of range" if ($height > 100);    ## you d
+ecide what to do
   substr($Plot[$n_iters],$height,1) = '*';
   
   if ($fill)
   {
       substr($Plot[$n_iters],$_,1)= '*' for (0..$height-1);   #don't 
+need a loop but
                                                               #this w
+as easier 
   }
}


sub get_height  #converts for example: 8.4543 to 85
{
   my $value = shift;
   my $rounded_value = sprintf("%.1f",$value); #.1 precision #changed 
+fmt spec to f (duh!)
   return ($rounded_value * 10);
} 

sub dumpPlot
{
    print "$Plot[$_]\n" for ($min_iter..$max_iter);
}

__END__
note lines truncated (not full 101 characters).
minimum iter=200 ; maximum iter= 220
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