John Robertson

North Salt Lake, UT

john.jersdesk.com

Age: 43

I am a software developer. I am particularly fond of the areas:

  • artificial intelligence, computer vision & machine learning
  • high end graphics & image processing
  • games

As stackoverflow changed their icon in celebration for several days when the US Supreme court unlawfully legislated to make gay marriage legal, I will in turn address the matter in my stackoverflow profile. That is the only way I can, in good conscience, continue to participate in stackoverflow.

I stand by the bible's teachings on the matter of homosexuality. I am a member of the Church of Jesus Christ of Latter-Day Saints, also known as a Mormon. That means I consider homosexuality and related immorality to be a perversion. By contrast I consider marriage to be sacred. The court has no more right to redefine the family than government can change the fact that men are born with God given inalienable rights.

I am also a mathematician.
I quite like interesting games and enjoy playing them with those of my many wonderful children who are old enough. We will often edit what we might find to be sleazy in a game without altering the game play, which quite widens the range of games we can play while staying within what we consider to be gospel standards.

1d
comment Is $\frac{\textrm{d}y}{\textrm{d}x}$ not a ratio?
Tangent manifold is the tangent bundle. And what it means is that dy and dx are both perfectly well defined functions on the tangent manifold, so we can divide one by the other giving dy/dx. It turns out that the value of dy/dx on a given tangent vector only depends on the base point of that vector. As its value only depends on the base point, we can take dy/dx as really defining a function on original space. By way of analogy, if f(u,v) = 3*u + sin(u) + 7 then even though f is a function of both u and v, since v doesn't affect the output, we can also consider f to be a function of u alone.
Jul
2
comment Precise rules for MTG
No, we bought a box of MTG cards. It is a common starter type box. It came with a fold out set of rules. They were incredibly vague. It was what came with the game, so to speak.
Jun
25
revised How do I select an inline svg by id using d3
added 2 characters in body
Jun
25
asked How do I select an inline svg by id using d3
Jun
24
awarded Famous Question
Jun
23
comment Is there a trick to separate an old photo moisture-fused to glass?
The glass had cracked on one photo, and we recovered quite a bit more near the crack and photo edges. We also went way, way past 20 minutes allowing the edges to fray, as the center was more important. Cracking the glass intentionally poses obvious risks. But I kind of wonder if breaking the glass more before soaking might have actually worked better. Maybe, maybe not, and no way to know offhand.
Jun
23
comment Is there a trick to separate an old photo moisture-fused to glass?
I think it was our best hope and very clever, but we still had a lot that wouldn't separate from the glass.
Jun
22
asked How is depth of field usually measured and how can I get depth of field measurements for a lens
Jun
21
awarded Popular Question
Jun
15
comment How to ensure method calls in a returned object literal use the intended "this"
@cdhowie, Are you sure. I was pretty sure that if I called a function with new then the returned value of the function was ignored UNLESS it was an object, in which case, new will elect to return the object the function returns instead of the object created by the invocation of new. (So, yes, the object initially created by new is actually left for garbage collected)
Jun
15
revised How to ensure method calls in a returned object literal use the intended "this"
added 33 characters in body
Jun
15
revised How to ensure method calls in a returned object literal use the intended "this"
added 209 characters in body
Jun
15
comment How to ensure method calls in a returned object literal use the intended "this"
@cdhowie So I create a number of instances of this object via "new". Call one of them X. Then I want to use X.methodA as a mouse event handler, e.g. I have jquery code that attaches mouseup on a dom element to X.methodA. But that looks like $("#domElementId").mousemove(X.methodA) But when mousemove is called, the "this" variable used in methodA no longer points to X as I understand. Feel free to correct me if I am wrong. Specifically, calls within method A to, say, method B will fail because they have do be done using this.methodB and "this" points to the global object.
Jun
15
comment How to ensure method calls in a returned object literal use the intended "this"
@JamesMontagne .Great clarifying question. I want it to point to the returned object. I suppose I thought that was the typical scenario for this sort of code, and didn't recognize the ambiguity. My fault. I have used javascript all of a month and a half so still sorting things out.
Jun
15
asked How to ensure method calls in a returned object literal use the intended "this"
Jun
9
comment Truncate (not round off) decimal numbers in javascript
I agree with Thomas. The difference in perspective may come with whether you are usually truncating for display, or for computation. From a computational perspective, this avoids "arithmetical artifacts"
Jun
6
awarded Notable Question
May
29
awarded Scholar
May
29
accepted Converting between wgs84 and nad83
May
26
awarded Taxonomist
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