The Lounge of Terrestrial Wheelmen

[G'day Mate]

Michele Scarponi killed on the road

[Blerpa]

Michele Scarponi killed on the road

Yes
Michele was going down while a local van driver was going up getting in the instersection and didn't give him right of way (He said he didn't even notice him): there was a full frontal, Michele died instantly.
This happened in Scarponi's home village. The van driver is accused of road kill, a recently added and updated crime to our road code - and yet lacking some rules concerning cyclist' safety.

[Tom Servo]

He said he didn't even notice him

Ahh yes, the passive way of saying "I didn't look."

RIP.

[Cam]

At least it's a crime in Italy. If it happened here the cop would pat the van driver on the back and say case closed.

[G'day Mate]

Here a cement truck driver got away with killing a cyclist basically saying "I thought there was enough room to pass"

[SportWagon]

Not sure what the CGI is written in (perl?), but it might be a fun exercise for me to convert it to something that'll run natively on Windows/Mac/Android (probably not iOS since I think you have to have a non-free developer license for that) if you feel like sharing the source code. No promises, but I've been meaning to poke around in some .Net lately, or might even be able to redo it in Javascript with React/React Native.

I looked at my perl source and realized it is an odd mixture of a set of web utilities someone else wrote, and various other kludgery on my part.

It ought to be possible to rewrite it in JavaScript. Then it wouldn't use any extra server resources. And then it could be made to run if accessed as an HTML text file using a browser on a smart device. (On Android, anyway).

I once rewrote a similar set of pages (my car finders) from perl to JavaScript. It was a project for two weeks of holidays.

This one is simpler in most ways, and slightly more complex because of its variable output. But I'd guess all that is algorithmically worked out and would just need converting.

Neither project requires much of JavaScript beyond emitting simple HTML after calculations. No dynamic reaction to user input, etc.

But I never became intuitively familiar with JavaScript, and it would probably take me a similar effort to convert this, and I don't foresee having such time in the near future.

There is obviously a generalization possible, where you could have arbitrary numbers of numerators and denominators with arbitrary labellings and scale factors. And possibly additive offsets, also.

(For instance, I might get around to making a bicycle version sometime so you can enter 48 for the chainwheel instead of 1/48).

Are you saying you can't host your own CGIs on an iOS web server?

[Tom Servo]

Well, the idea was to build something that could even run natively. React Native lets you write stuff in Javascript using Facebook's React framework and compile it to mobile native code, so it could actually just be installed as an app. That's pretty easy to sideload onto Android, but iOS is tougher in that regard, and they charge a significantly higher amount to get something in the app store (I think it's a $25 lifetime fee for Android, it's $99 a year for an individual developer on iOS).

I've done a little messing around with React but haven't done much. As far as I know, the mobile Facebook app is written in React and compiled with Native, so it seems pretty doable, and would mean the same code could run on a webpage with no server-side code needed and also run as an app on a device.

But really, it was more an excuse to have something to fiddle with.

[SportWagon]

But really, it was more an excuse to have something to fiddle with.

Here is the command-line perl called by the CGI.

Example (UNIX-like) command lines...

% ./gears gear=3.0,2.5,2.0,1.5,1.0 final=4.0 rpm=1000-10000x1000 mph= tire=26.0 reorder=tire,final
% ./gears gear=3.0,2.5,2.0,1.5,1.0 final=4.0 rpm=1000-10000x1000 mph= tire=26.0 reorder=tire,final output=web
% ./gears gear=3.0,2.5,2.0,1.5,1.0 final=4.0 rpm=1000-10000x1000 mph= tire=26.0 reorder=tire,final output=web | lynx -stdin

(Part 1 only, because it's too long for the board...

Spoiler:

#!/usr/bin/perl -w

require 5.002;
use strict;

sub
warn {
	print @_;
}

#
# This program uses obvious algorithms to fill in the fifth value
#   when four values are specified.  It works with the following
#   specific equality...
#
#  
#           rpm       T
#  mph  = ------- * -----
#          G * F      W
#
#
# but could be generalized to work with any basic formula which is
#   a simple quotient of products.
#
#

$main::wheel_const = 88;    # 88 for circumference in feet
$main::wheel_const = 336;    # 336.X for diamter in inches

sub
give_mph {
	my($mph,$rpm,$tire,$gear,$final) = @_;

#print "give_mph($mph,$rpm,$tire,$gear,$final)\n";
	$mph = $rpm / ($gear * $final);
	$mph *= $tire / $main::wheel_const;
	return $mph;
}

sub
give_final {
	my($mph,$rpm,$tire,$gear,$final) = @_;

#print "give_mph($mph,$rpm,$tire,$gear,$final)\n";
	$final = $rpm / ($mph * $gear);
	$final *= $tire / $main::wheel_const;
	return $final;
}

sub
give_gear {
	my($mph,$rpm,$tire,$gear,$final) = @_;

#print "give_mph($mph,$rpm,$tire,$gear,$final)\n";
	$gear = $rpm / ($mph * $final);
	$gear *= $tire / $main::wheel_const;
	return $gear;
}

sub
give_rpm {
	my($mph,$rpm,$tire,$gear,$final) = @_;

#print "give_mph($mph,$rpm,$tire,$gear,$final)\n";
	$rpm = $mph * $final * $gear * $main::wheel_const;
	$rpm /= $tire;
	return $rpm;
}

sub
give_tire {
	my($mph,$rpm,$tire,$gear,$final) = @_;

#printf("give_tire($mph,$rpm,$tire,$gear,$final);\n");
	$tire = $mph * $final * $gear * $main::wheel_const;
	$tire /= $rpm;
	return $tire;
}

sub
mytype {
	my($s) = @_;

	return 2 if ( $s =~ /[x,\-]/ );   # range
	return 1 if ( $s =~ /\d/ );   # number
	return 0 ;   # something else, probably empty
}

sub
expand {
	# expand a range
	my($which1, $s) = @_;
	my($step) = 1;   # need to pass default...
	my($t,$low,$high,$i);
	my(@v) = ();
	my(@temp) = split(/,/,$s);

	if (defined($main::defstep[$which1])) {
		$step = $main::defstep[$which1];
	}
	foreach $t (@temp) {
		if ($t =~ /x/) {
			$step = $t;
			$step =~ s/.*x//;
			$step =~ s/[^.\d]//;
			# more syntax checking needed
			if ($step <= 0) {
				$step = 1;
			}
			$t =~ s/x.*//;
		}
		if ($t =~ /\-/) {
			($low,$high) = split(/\-/,$t);
			# more syntax checking needed
			for ($i = 0; $i < 50 && $low <= $high; ++$i) {
				push @v,$low;
				$low += $step;
			}
		}
		else {
			push @v,$t;
		}
	}
#print("expand $s to @v\n");
	return @v;
	
}

#
# &print_range($which1,$which2,@range);
#
# print the give range to use as column headings...
#
sub
print_range {
	my($which1,$which2,@range) = @_;
	my($i,$s);
	my($title) = $main::names[$which1];
	my($tformat,$fillpad);
	my($centrepad) = int((1 + ($#range+1)*7 - length($title))/2);
	$centrepad = 0 if ($centrepad < 0);

	$tformat = $main::format[$which1];
	if ($main::output eq "web") {
		printf("<table>\n");
		$main::intable = 1;
		printf("<tr><th>&nbsp;</th><th colspan=%d align=center>%s</tr>\n",
					$#range+1,$title);
		$tformat = "<th rowspan=2>" . $tformat . "</th>";
		printf("<tr><th></th>");
	}
	else {
		printf("%9.9s%*s%s\n","",$centrepad,"",$title);
		printf("%9.9s","");
	}
	for ($i = 0; $i <= $#range; ++$i) {
		printf($tformat, $range[$i]);
	}
	$title = $main::names[$which2];

	if ($main::output eq "web") {
		printf("</tr>\n");
		printf("<tr><th>%s</th></tr>",$title);
	}
	else {
		$centrepad = int((1 + 9 - length($title))/2);
		$centrepad = 0 if ($centrepad < 0);
		$fillpad = 9-length($title)-$centrepad;
		$fillpad = 0 if ($fillpad < 0);
		printf("\n%*s%s%*s",$centrepad,"", $title, $fillpad,"");
		$s = sprintf($main::format[$which1], 0.0);
		$s =~ s/./-/g;
		$s =~ s/^./ /;
		for ($i = 0; $i <= $#range; ++$i) {
			printf("%s", $s);
		}
	}
	printf("\n");
}

# &print_all_const(@seen,@values);
sub
print_all_const {
	my(@vector) = @_;
	my(@myseen) = @vector[0..$#main::names];
	my(@myvalues) = @vector[$#main::names+1..$#main::names+1+$#main::names];
	my($rawi,$i,$f,$v,$x);

	if ($main::output eq "web") {
		if ($main::intable) {
			printf("</table>\n<hr>\n");
			$main::intable = 0;
		}
		printf("<table>");
	}
	printf("\n");
	for ($rawi = 0; $rawi <= $#main::names; ++$rawi) {
		$i = $main::reorder[$rawi];
		if ($myseen[$i] == 1) {
			if ($main::output eq "web") {
				printf("<tr><th>%s</th><td>", $main::names[$i]);
				printf($main::format[$i] . "</td></tr>\n",
						$myvalues[$i]);
			}
			else {
				printf("%6s= " . $main::format[$i] . "\n",
					$main::names[$i], $myvalues[$i]);
			}
		}
	}
	if ($main::output eq "web") {
		printf("</table>");
	}
	printf("\n");
}

sub
print_cell {
	my($ishead,$which, $value) = @_;
	my($tformat);

	$tformat = $main::format[$which];
	if ($main::output eq "web") {
		if ( $ishead ) {
			$tformat = "<th>" . $tformat . "</th>";
		}
		else {
			$tformat = "<td>" . $tformat . "</td>";
		}
	}
	else {
		if ( $ishead ) {
			$tformat = $tformat . ": ";
		}
	}
	printf($tformat, $value);
}

# &solve($total,$level,$left,$value,$valuei,@seen,@values);
sub
solve {
	my($total,$level,$left,$value,$valuei,@vector) = @_;
	my(@myseen) = @vector[0..$#main::names];
	my(@myvalues) = @vector[$#main::names+1..$#main::names+1+$#main::names];
	my($rawi,$i,$f,$v,$x,$nextwhich);

	#printf ("%d %d %d %d\n", $#myseen, $#myvalues, $myseen[0], $myvalues[4]);
	if ($left == 2 || ($left == 1 && $total == 1) || $total == 0 ) {
		print_all_const(@myseen,@myvalues);
	}
	if ($left == 2 ) {
		# determine the values we are about to traverse...
		$nextwhich = 0;
		for ( $rawi=0; $rawi <= $#main::names; ++$rawi) {

			$i = $main::reorder[$rawi];
			if ($myseen[$i] == 2) {
				$nextwhich = $i;
				last;
			}
		}
		# determine next range, and print it...
		for ( $rawi=$#main::names; $rawi >= 0; --$rawi) {
			$i = $main::reorder[$rawi];
			if ($myseen[$i] == 2) {
				my(@myrange) = &expand($i,$myvalues[$i]);
				print_range($i,$nextwhich,@myrange);
				last;
			}
		}
	}
	for ( $rawi=0; $rawi <= $#main::names; ++$rawi) {
		$i = $main::reorder[$rawi];
		if ($myseen[$i] == 2) {
			my(@myrange) = &expand($i,$myvalues[$i]);
			if ($left == 1 && $total >= 2) {
				printf("<tr>") if $main::output eq "web";
				print_cell(1,$valuei, $value);
			}
			foreach $v (@myrange) {
				if ($total == 1 ) {
					print_cell(1,$i, $v);
				}
				$myseen[$i] = 1;
				$myvalues[$i] = $v;
				&solve($total,$level+1,$left-1,$v,$i,@myseen,@myvalues);
				if ($total == 1 ) {
					printf("\n");
				}
			}
			if ($left == 1 && $total >= 2) {
				printf("</tr>") if $main::output eq "web";
			}
			print("\n");
			return;
		}
	}
	for ( $rawi=0; $rawi <= $#main::names; ++$rawi) {
		$i = $main::reorder[$rawi];
		if ($myseen[$i] == 0) {
			$f = $main::solvers[$i];
			$x = &{$f}(@myvalues);
			print_cell(0,$i,$x);
			last;
		}
	}
}

#
# mapname($name)
#   return the index in $main::names of the given name
#
sub
mapname {
	my($name) = @_;
	my($i);

	$name =~ s/es$//;
	$name =~ s/s$//;
	for ( $i=0; $i <= $#main::names; ++$i) {
		if ($main::names[$i] eq $name) {
			return $i;
		}
	}
	return -1;
}

#
# set_reorder($string)
#
#   This interprets a string to represent the way to reorder examination
#   of the variables.
#
#   String should consist of numbers or the names separated by commas
#
sub
set_reorder {
	my($s) = @_;
	my(@seen) = @main::reorder;
	my($i,$old,@v);

	for ($i = 0; $i <= $#seen; ++$i) {
		$seen[$i] = 0;
	}
	@v = split(/,/,$s);
	for ($i = 0; $i <= $#seen; ++$i) {
		$v[$i] = "0" if (!defined($v[$i]));
		$v[$i] =~ s/\s*//g;
		if ( $v[$i] !~ /^\d+$/) {
			$v[$i] = &mapname($v[$i]);
		}
		$v[$i] = 0 if ($v[$i] < 0);
		$v[$i] = 0 if ($v[$i] > $#seen);
		$old = $v[$i];
		while ($seen[$v[$i]]) {
			# rather than generate diagnostics,
			# force a bad mapping to be some good mapping
			++$v[$i];
			$v[$i] = 0 if ($v[$i] > $#seen);
			last if ($v[$i] == $old);
		}
		$seen[$v[$i]] = 1;	
	}
#print "reorder = @v\n";
	return @v;
}

[SportWagon]

Part 2

Spoiler:

	

# main line starts here...

my($x,$i);


my(@vector) = (144, 6000, 24.0, 0.9, 3.3);
my($f);

my(@seen) = (0,0,0,0,0);

$main::intable = 0;    # set when we print "<table>"

$main::reorder_set = 0;
@main::reorder = (0,1,2,3,4);

@main::solvers = (\&give_mph,\&give_rpm,\&give_tire,\&give_gear,\&give_final);
@main::names =  ("mph",  "rpm",  "tire", "gear", "final");
@main::format = ("%7.1f","%7.0f","%7.2f","%7.3f","%7.3f");
@main::defstep =  (5,  500,  0.5, 0.2, 0.1);
$main::output = "text";
(
 $main::XMPH,
 $main::XRPM,
 $main::XTIRE,
 $main::XGEAR,
 $main::XFINAL
) = ( 0, 1, 2, 3, 4);
@vector = (   # dummy use of the symbols...
 $main::XMPH,
 $main::XRPM,
 $main::XTIRE,
 $main::XGEAR,
 $main::XFINAL
) ;
@vector = (0,0,0,0,0);
my(@values) = (0,0,0,0,0);
my($reorder_str) = "";

while ( defined($ARGV[0]) ) {
	my($temp,$param,$value,$i);
	$temp = $ARGV[0];
	if ( $temp =~ /^output=/i ) {
		$temp =~ s/^output=//i;
		$main::output = $temp;
	}
	elsif ( $temp =~ /^reorder=/i ) {
		$temp =~ s/^reorder=//;
		@main::reorder = &set_reorder($temp);
		$main::reorder_set = 1;
	}
	elsif ( $temp =~ /=/ ) {
		$temp =~ /^([^=]*)=([^=]*)$/;	
		$param = $1;
		$value = $2;
		$i = &mapname($param);
		if ( $i >= 0 ) {
			$seen[$i] = &mytype($value);
			$values[$i] = $value;
			$vector[$i] = $value;
			$reorder_str .= "$i,";
		}
		else {
			&warn("Unknown parameter in \"$temp\"\n");
		}
	}
	else {
		&warn("Bad argument \"$temp\"\n");
	}
	shift @ARGV;
}

if ($seen[$main::XTIRE]) {
	my($temp) = $vector[$main::XTIRE];
	$temp =~ s/,.*//;
	$temp =~ s/-.*//;    # get first number only
	if ($temp =~ /^\d[.]/ ) {
		$main::wheel_const = 88;    # 88 for circumference in feet
	}
	if ($temp == 0.0 ) {
		$seen[$i] = 0;
		$values[$i] = "";
		$vector[$i] = "";
	}
}

if ($main::reorder_set == 0) {
	@main::reorder = &set_reorder($reorder_str);
}


#for ( $i=0; $i <= $#names; ++$i) {
#	printf("%d:%s:%.3f\n",$seen[$i],$names[$i],$vector[$i]);
#}

my($count) = 0;
my($rawi);
$count = 0;
for ( $i=0; $i <= $#main::names; ++$i) {
	if ($seen[$i] == 2) {
		++$count;
	}
}
#
# Output, especially Web output, got confused if there were fewer than
#   two ranges, so let's arrange to force two ranges...
#
for ($rawi = $#main::names; $count < 2 && $rawi >= 0; --$rawi) {
	my($i) = $main::reorder[$rawi];
	if ($seen[$i] == 1) {
		$seen[$i] = 2;
		++$count;
	}
}

&solve($count,0,$count, 0,0, @seen,@values);

printf("\n");
if ($main::output eq "web" && $main::intable) {
	printf("</table>\n");
	$main::intable = 0;
}

[Tom Servo]

I am both excited to tackle this and reminded of why I don't do a lot of perl coding these days.