Wesley Burr

@wsburr
23 Followers
137 Following
45 Posts
Stats prof at Trent University; member of TIES and SSC
Show threadWesley BurrFeb 23

@dlakelan I think the phase is 2 when considered on a standardized period of 2pi.

Then it's pi/4 as frequency (or (2pi)/(pi/4)=8 for period) and the 2 units of translation in the default domain turn into pi/2 units in the absolute domain.

So take pi/2 * (8/(2pi)) = 2. Or just pi/2 * (1/(pi/4)) if that's easier to understand.

Show threadWesley BurrFeb 23
@dlakelan Totally fair. As you said, foo. Relative phase and absolute phase are different things. I believe the default in these calculus courses is relative phase, chosen so you're measuring the something on the scale of one "period unit" rather than an absolute offset.
Show threadWesley BurrFeb 23
@dlakelan (and of course, period is actually 2*pi/B, not straight B)
Show threadWesley BurrFeb 23

@dlakelan so in his case:

* sec(x)
* sec(x-2)
* sec(pi/4(x-2))
Fin.

There's no amplitude transformation or vertical translation. A=D=1.

Show threadWesley BurrFeb 23

@dlakelan I think he would be "right" under most definitions. Phase is only measured as a standalone when you can write the first piece as a 2*pi*x structure.

If you think of it as a translation in x, followed by a transformation in x, then transformation in y, then translation in y, that's the convention for taking a default trig function to a modified form. So you work in reverse to return it to standard form, then read off the A,B,C,D from A*trig(B*x + C) + D.

Wesley BurrDec 17
Sascha WolferDec 16

When #teaching #Rstats / #statistics courses, I (and several colleagues of mine) made the experience that it is indeed pretty hard for a lot of students to cope with the file system on their computer. They have questions like: How do I know the "path" of a file? How do I control in which directory something is saved? WHY DO I NEED THIS?!?

I don't want to make fun of these students because I know that this could be because operating systems are increasingly obscuring file/directory systems from their users.

But if I want to teach students to use a scripting/ #programming language independently, that's a real problem!

So my questions to you are: Do you have the same impression when teaching? And if so: How do you deal with this from a teaching perspective? To be honest, I don't want to use precious course time to teach the absolute basics of computers' file systems in the first session(s).

Show threadWesley BurrDec 17

@sascha_wolfer Yes, 100%, yes. This has been a problem for over a decade. I have videos for the major OSs showing them steps to set up a single "course directory" and then explicitly enforce a bad workflow where they store every file in one place.

We do a lot of file I/O, so they get to practice moving their downloads into a spot and then reading them in from Quarto documents. With many errors: I have a stickied flowchart for when they claim they've "done everything" and "it just doesn't work"

Wesley BurrDec 5
@adamhsparks You as well! The world is strangely small sometimes.
Show threadWesley BurrNov 9
@dlakelan that's pretty crazy to have it spike that far just off ambient.
Show threadWesley BurrNov 9
@dlakelan I'll see spikes like that when we start the evening kitchen use. Electric range, no gas, but still the act of cooking puts off a lot of VOCs. Need to finish the retrofit and put in an actual external exhaust and see if it removes that source.