On 1/7/13 4:30 AM, Bob Camp wrote:> HI

don't need Matlab very badly. Around here a typical Matlab setup is
indeed CPU bound for a lot longer than that during a normal work day.
Two or three hours a day is not at all unusual.

I do tons of stuff on Matlab that runs in seconds, because it's a easy
and facile development environment. Here's a time-nutsy sort of example..

I've been working on systems for time and frequency distribution among
orbiters and landers at a planet.  Say you're flying one of those
newfangled Deep Space Atomic Clocks on an orbiter, and you want to
propagate that to other orbiters or landers.  The questions that come up
are things like "how much RF power do we need to radiate", "what
performance is achievable at the lander, for an orbiter with orbit
parameters X and Y"..

So you've got to run an orbit propagator, then take that data and run it
through some sort of ad-hoc models for the time/frequency transfer
performance, and then take that and come up with some meaningful plots
to put on a slide or in a report.  And then, someone asks, ok, that was
for a 400km circular orbit around Titan, but what if we make it
elliptical with a 2000km apoapsis, oh, and by the way, what's the
maximum time we can NOT run the transmitter during periapsis, and still
get decent nav performance.

sure, I could load up the orbits in something like STK or SOAP, generate
a file of positions or link analysis, then ingest that into something
that does the time analysis, etc.

Or, I can just use an existing Matlab toolbox that does the orbit
propagator, run it through the existing Matlab code that does the link
and time modeling, and use Matlab to generate the pretty plots.  And
when the weird question comes up, I can just change a few numbers,
re-run it, see that it's going to be a disaster, performance wise, go
back to them and say, "are you sure you want to do that, why not a 1200m
apoapsis?" or something like that.

There's a whole lot of stuff that time-nuts do in terms of data analysis
that is pretty quick and easy in Matlab (or Octave), especially for
"fooling around".  I'm not wild about Matlab's data acquisition
capabilities, but then, I'm less wild about LabView (because under it
all, I'm a "edit the text file, compile and run" kind of guy).

And if you're doing something like filters and control loops, Matlab
makes it pretty easy, and has a lot of library stuff.  Granted, all this
also exists for most other languages, e.g. Python.

A couple years ago, I was trying to figure out a way to measure the gain
and noise behavior of a GPS receiver with just the raw bits from the
sampler.  Matlab makes it easy to generate data and do the analysis.

Ultimately, Matlab (and related products) saves developer time which is
expensive.  It's faster (wall clock wise) to just call a toolbox routine
to, say, do some curve fit or digital filter than it is to code it up in
something else.  This is especially true when the developers are more
domain knowledge specialists rather than software engineers: they like
using Matlab, they're familiar with it.

On Mon, 07 Jan 2013 06:40:12 -0800
Jim Lux jimlux@earthlink.net wrote:

Apropos: Any good recomendation for a book/website/or similar to learn
matlab/octave?

		Attila Kinali

--
The trouble with you, Shev, is you don't say anything until you've saved
up a whole truckload of damned heavy brick arguments and then you dump
them all out and never look at the bleeding body mangled beneath the heap
-- Tirin, The Dispossessed, U. Le Guin

The tutorials that come as part of the octave documentation
package are quite good.

-Chuck Harris

Attila Kinali wrote:

An semester or two with linear algebra is an good start, but the homepage
of matlab have an excelent learning section.

No experience with Octave yet.

MIT OCW (open courseware) have lectures on linear algebra, in addition to
most of the other courses offered at MIT.

BR.
Thomas.

2013/1/7 Attila Kinali attila@kinali.ch

--

Please  avoid sending  me  Word  or  PowerPoint  attachments.
See  http://www.gnu.org/philosophy/no-word-attachments.html
PDF is an better alternative and there are always LaTeX!

Hi

It being lunch time, I got out my stopwatch. On my machine here, Matlab
takes a bit over 30 seconds to load. FDATool takes another 30 seconds to
load. Loading a saved session on a fairly simple FIR  into FDATool adds a
bit over a minute. If I tell it I want to load a fairly complex FIR that
bumps it up to three minutes. None of that actually involves any "work",
that's just bringing up the session. Yes, it does a bunch of math to do the
display, and that's why it takes a while.

The machine has it's own license, so it's not waiting on FlexLM to do some
mumbo jumbo. Nothing else was running on the machine.

This is not something I would want to try on a single core running at 500
MHz...

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Jim Lux
Sent: Monday, January 07, 2013 9:40 AM
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] matlab, python, etc.

On 1/7/13 4:30 AM, Bob Camp wrote:> HI

don't need Matlab very badly. Around here a typical Matlab setup is
indeed CPU bound for a lot longer than that during a normal work day.
Two or three hours a day is not at all unusual.

I do tons of stuff on Matlab that runs in seconds, because it's a easy
and facile development environment. Here's a time-nutsy sort of example..

I've been working on systems for time and frequency distribution among
orbiters and landers at a planet.  Say you're flying one of those
newfangled Deep Space Atomic Clocks on an orbiter, and you want to
propagate that to other orbiters or landers.  The questions that come up
are things like "how much RF power do we need to radiate", "what
performance is achievable at the lander, for an orbiter with orbit
parameters X and Y"..

So you've got to run an orbit propagator, then take that data and run it
through some sort of ad-hoc models for the time/frequency transfer
performance, and then take that and come up with some meaningful plots
to put on a slide or in a report.  And then, someone asks, ok, that was
for a 400km circular orbit around Titan, but what if we make it
elliptical with a 2000km apoapsis, oh, and by the way, what's the
maximum time we can NOT run the transmitter during periapsis, and still
get decent nav performance.

sure, I could load up the orbits in something like STK or SOAP, generate
a file of positions or link analysis, then ingest that into something
that does the time analysis, etc.

Or, I can just use an existing Matlab toolbox that does the orbit
propagator, run it through the existing Matlab code that does the link
and time modeling, and use Matlab to generate the pretty plots.  And
when the weird question comes up, I can just change a few numbers,
re-run it, see that it's going to be a disaster, performance wise, go
back to them and say, "are you sure you want to do that, why not a 1200m
apoapsis?" or something like that.

There's a whole lot of stuff that time-nuts do in terms of data analysis
that is pretty quick and easy in Matlab (or Octave), especially for
"fooling around".  I'm not wild about Matlab's data acquisition
capabilities, but then, I'm less wild about LabView (because under it
all, I'm a "edit the text file, compile and run" kind of guy).

And if you're doing something like filters and control loops, Matlab
makes it pretty easy, and has a lot of library stuff.  Granted, all this
also exists for most other languages, e.g. Python.

A couple years ago, I was trying to figure out a way to measure the gain
and noise behavior of a GPS receiver with just the raw bits from the
sampler.  Matlab makes it easy to generate data and do the analysis.

Ultimately, Matlab (and related products) saves developer time which is
expensive.  It's faster (wall clock wise) to just call a toolbox routine
to, say, do some curve fit or digital filter than it is to code it up in
something else.  This is especially true when the developers are more
domain knowledge specialists rather than software engineers: they like
using Matlab, they're familiar with it.

time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

I think you have it backwards.  The purpose of Matlab and things like it
is NOT to save computer time.  It is to have enginerring man hours.  For
example a problem can be coded in two hours in Matlib that would take me a
week to code in C.  But then when you run the software the C coded
solution might run 10X faster and be done in minutes rather than hours.
But look at the TOTAL time, a day for Matlab a Week for C.  We save much
time and money but we used the computer harder.    Of course those numbers
are just round examples.

If you are building a production system and intend to distribute many
thousands of units then saving cost of the parts matters but if you are
building just 5 or 10 units then the cost of the engineering dominates and
you almost don't care the cost of the parts.    This is the Matlab/C
des=cision too, using something like LabView or Matlab reduces engineering
costs but pushes it out to execution costs.  It depends how many times the
code will be run.  If you will be running it thousands of times per week,
code it in C

On Mon, Jan 7, 2013 at 6:40 AM, Jim Lux jimlux@earthlink.net wrote:

--

Chris Albertson
Redondo Beach, California

Hi

The original spec called out "needs to run Matlab". If that's already a
given, then CPU horsepower is the variable to optimize vs payroll hours.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Chris Albertson
Sent: Monday, January 07, 2013 12:44 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] matlab, python, etc.

I think you have it backwards.  The purpose of Matlab and things like it
is NOT to save computer time.  It is to have enginerring man hours.  For
example a problem can be coded in two hours in Matlib that would take me a
week to code in C.  But then when you run the software the C coded
solution might run 10X faster and be done in minutes rather than hours.
But look at the TOTAL time, a day for Matlab a Week for C.  We save much
time and money but we used the computer harder.    Of course those numbers
are just round examples.

If you are building a production system and intend to distribute many
thousands of units then saving cost of the parts matters but if you are
building just 5 or 10 units then the cost of the engineering dominates and
you almost don't care the cost of the parts.    This is the Matlab/C
des=cision too, using something like LabView or Matlab reduces engineering
costs but pushes it out to execution costs.  It depends how many times the
code will be run.  If you will be running it thousands of times per week,
code it in C

On Mon, Jan 7, 2013 at 6:40 AM, Jim Lux jimlux@earthlink.net wrote:

a

run

mailman/listinfo/time-nuts<https://www.febo.com/cgi-bin/mailman/listinfo/tim
e-nuts>

--

Chris Albertson
Redondo Beach, California

time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
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and follow the instructions there.