Re: BLT Problems

[glen e. p. ropella]

Todd,

I'm not sure if this might be why or not.  I've been using Slackware
for a while (with the 1.2.13 and with the 2.0.0 kernels with gcc
2.7.2, etcetc) and I've never seen this.

Anyway, what I think is happening is that heatbugs has a call to the
"-step" method on an ActiveGraph, which then calls the "-addX:
(double) x Y: (double) y" method on a GraphElement in BLTGraph, which
then calls the "-append" method on a BLTVector.

The call to addX:Y: (in ActiveGraph.m) looks like:

  [element addX: getCurrentTime() Y: [self doubleDynamicCallOn: dataFeed]];

Now, getCurrentTime() probably returns an unsigned integer because 
it's defined in activity.h as:

   typedef unsigned   timeval_t;        // type for time values


This means that the first arguement for addX is the wrong type.
So, you might try changing the addX call to:

  [element addX: (double) getCurrentTime() Y: [self doubleDynamicCallOn: 
dataFeed]];

And see if the problem goes away.  I doubt it will.  But, who knows.
The reason I doubt it is because I have no idea why it would balk at
the append method on BLTVector instead of higher up in the stack.  If
presented with the circumstance without the error message, I would say
that it would fail to find the "-addX: (unsigned) x Y: (double) y"
method and the error message would say:

   GraphElement does not respond to method addX


Anyway, give it a shot and let me know how it goes.

glen


> I have been trying to get swarm working for weeks.  I think I'm close to
> having it working, but it's still not quite right.
> 
> I am runing Red Hat 3.0.3 Linux kernel 1.2.13 on a Pentium Pro 200
> machine.
> 
> I have installed all of the required libraries.  There did not appear to
> be any errors during the install process. The swarm libraries and the
> sample apps also appeared to compile without incident.  The problems
> occur when I run the sample apps.  For example, when I run heatbugs, the
> message,
> 
>       BLTVector does not respond to method append
> 
> appears repeatedly in the xterm window from which I executed heatbugs,
> and the 'happiness of bugs vs. time' graph is not displayed when the go
> button is pressed.  On the up side, the heatbugs seem to be scampering
> around properly in their window.
> 
> What am I doing wrong?  I have been through the entire install process
> no fewer than five times with exactly the same result.
> 
> Thanks,
> 
> 
> Todd Allen