fluorinerocket

Insane to me that someone would use a windows machine to run a piece of equipment when PLCs exist and are supported for decades by companies like Rockwell, Siemens, Allen Bradley

Terrible explanation

Why don't the "In my country" posters ever name the country

I am certainly in the minority and I do live with it.

Things like motion sensor lights, faucets that turn off so quickly that you have to hold your hands in weird position to wash them, 1.6 gallon flush toilets are all completely avoidable things that are forced on us by a misguided sense of doo gooding.

These so called innovations are WORSE than what they replaced, less reliable, and often are so badly designed they accomplish the exact opposite of what they are intended to do.

A increasing retry time motion sensor light switch is a good idea. But then again, wherever these things are installed, they go with the cheapest thing that to meet code and get whatever energy certification.

Zero Fs are given by the people who don't have to use the room. The worst thing will be what is used. That is my experience.

Oh you want to change the timersetting? Guess what that's on a dip switch behind the face plate, and you need to find and shut off the breaker and pull the thing from the wall. Put in a ticket to facilities, we'll get to it never

Yes let's make you flush 5 times to save 0 water over a conventional while we run the sprinklers to keep our immaculate lawn green during a 105 degree summer.

Want to take a nice 5 gpm shower? No, you need to let almond farmers drain the river before it gets to the ocean so everybody can have almond milk. Stay in there twice as long buddy, don't know what to tell you.

Yes there are a bunch of terrible ideas in this thread. Video camera controlled lights? Yes f privacy of everyone to save a few bucks? well I think that was sarcastic

Motion controlled lights are always timed badly, incredibly annoying to have them switch off when you are sitting still working or taking a duece.

How about the janitor shuts off the lights after everyone goes home?

Can we please ban university press releases

Statecharts are one of the those concepts that are extremely useful for machine control that it seems crazy to me that they are so little adopted from what I have seen. At most people might know about a flat mealy state machine.

What's better than graphically designing your HSM, simulating it vs all kinds of scenarios to verify it, and auto generating the code?

There were so many things that NI did that were great. Debugging in LabVIEW was also very easy with probes, conditional breakpoints etc.

It's really too bad that it's more or less dead now

I am sure they each personally researched the topic very thoroughly to come to this conclusion

What if they have a bunch of prerecorded data for the guys heart, then use a lock in amplifier to see if there is a signal in the noise

https://en.wikipedia.org/wiki/Lock-in_amplifier

You're right but still, big error. I get its averaging over the range, and the floats are not uniformly distributed.

Maybe the thing to optimize the expression for is the minimize the maximum error, and not the average error. I think that's what I would care about

You're right I misread the graph. That said though I have played around with Herbie before, trying it out on a few of the more gnarly expressions I had in my code (analytical partial derivatives if equations of motion if launch vehicle in rotating spherical frame) and didn't see much appreciable improvement over the expected range of values, but then again I didn't check every single one.

What would be cool is if you could some how have this kind of analysis done automatically for your whole program where it finds the needle in the haystack expression that can be improved, assuming you gave expected ranges for your variables

How useful is this when you are using numbers in a reasonable range, like 10^-12 to 10^12? Generally I try to scale my numbers to be in this range, whether by picking the right units or scaling constraints and objectives when doing nonlinear programming/ optimization.

Like looking at this example,

https://herbie.uwplse.org/demo/b070b371a661191752fe37ce0321c...

It is claimed that for the function f(x) =sqrt(x+1) -1

Accuracy is increased by from 8.5% accuracy to 98% for alternative 5 Which has f(x) = 0.5x

Ok so x=99, the right answer is sqrt(100) -1 = 9

But 0.5 * 99 = 49.5 which doesn't seem too accurate to me.

The rocket company I worked at designed their orbital rocket in inches and lbm. Engine flow rates in lbm/s, temperatures in deg Rankine, thrust in lbf. Btu/hour/inch^2/degR heat transfer coefficients.

I miss fuckedcompany.com

How is that working out, genuinely curious

I don't think they even had a way to do dc-dc voltage step-up and step-down at high power and efficiency, needed semiconductors for that to do high speed switching in buck and boost converters

Awesome, I learned something about optics! I was afraid this was going to be about Haskell

I haven't ever experienced this yet, what packages were involved?

LabVIEW FPGA was amazing, I did all kinds of things with it on the compactRIO controller FPGA

You can write very neat and tidy code with dataflow diagram languages. I did it professionally for years, and there were many others who did as well.

Same thing as any other language, you have to come up ways to organize the code into functions and classes that make sense. Vomiting everything into the top level diagram is the same as 10000 line of code while(1)

You could always tell the exact level of proficiency someone had with LabVIEW immediately when opening the diagram.

The dataflow model maps very well to FPGAs IMO, it's a shame it never became widespread. There was much potential there

They like to say things like that or some version of "we want to teach the concepts, the specific technology changes too fast". Does it? Just seems lazy to me.

I on the other hand can't stand PDFs.

They take up valuable screen space, it is annoying to scroll to the sections you need. Yeah yeah some PDFs have the side navigation thing. Most don't

With a book I can put in those little flags to bookmark sections, I can easily riffle the pages and scan for the chapter I need, I can hand write in the margins

I often need 2 or 3 books open to different sections, I like keeping them on my desk so I can glance at them when I need to

I've probably cracked $1000 spent on books this year.

Rockets have flown to orbit on auto coded simulink, seen it myself

Would love to see a language in which hierarchical state machines, math/linear algebra, I/O to sensors and actuators, and time/timing were first class citizens.

Mainly for programming control systems for robotics and aerospace applications

When I was a kid in Italy in the late 80s early 90s the elentary school teachers also did "interrogazione" at the blackboard. That is individual kids would go up to the blackboard and get asked questions front of the rest of the class.

Not sure if those two were just old school (they'd occasionally hit us/ pull ears too) but damn was I ahead of all the other kids when I came back to the USA

Also the two teachers had the same class of kids for all of elementary school, teaching 1st through 5th grades sequentially So they got to know the kids quite well

So 12% of the population pays it? So more of a tax on the professional, works for a living, upper middle class?

Clear case on the terminal blocks could be nice, though might still get a bit tough to see when you have multi-level TBs all mounted in strip on DIN rail.

When I used to be involved in control panels I would always yank on all the wires too :-)

Yes I didn't realize anyone actually did anything numerical without numpy. I don't think I've ever imported python's math module once. Who in their right mind is making a 1e6 long python list

I still hate screw terminal blocks. Spring terminals + ferrules are still the way.

I just revised Matlab to do some work involving a simulation and Kalman filter, and after years of using python I found the experience so annoying that I really welcome this library.