# User Portlet

Eric Johnstone
Discussions
Kuba, The final line of your post solved my problem. Here is the test function that saves state for different names. test[name_String, init_Integer] := Block[{state}, If[NameQ[name "$"], (state = Symbol[name "$"];...
Hi David, I've been poring over the MMA Boolean functions. As usual in MMA, there is more than you could have imagined available. Here is my Boolean thread that I will be augmenting soon: http://community.wolfram.com/groups/-/m/t/1257404 ...
Thanks, Szabolcs. Well, the story behind my question is that I'm developing an environment for working with Boolean algebra in an engineering context. I've been fascinated by Boolean algebra since I read Boole's *Laws of Thought* when I was...
Sorry, when I posted it the first time, I got a message that some further classification was needed, so I added another one and posted. But it looks like the first one when through anyway. Eric
Mathematica doesn't use the usual boolean notation with which circuit designers are familiar. The plan is to enter boolean expression as a c d + b d not a + a not b not c (a not c not d + b not c not d) and produce overbars on the...
Hi Harun, I tried every possible permutation trying to find that local maximum. No deal. But even in Mathematica itself, which can access Alpha, your command could not zero in on the local maximum. However, when I asked for local maximum y...
If you include the equation for a: y=t-DT; DT=300 a/9.81; a=((B/2)^2/3)/((Tu/2)^2/3*(h-hv+tu)); hv=(Vi*d)/(4 B*(Tu/2)^2)^(1/3); B=Vi*g*d; g=(9.81 (t-x))/300; Vi=Q/l; In[34]:= y Out[34]= t-(0.0327 d^2...
Dynamic` has a second argument that gives the behaviour I'm looking for. Since the left-hand plot is too slow to move with the right-hand one, it can be disabled until the right-hand plot is in the desired position. When the mouse button is...
The solution was in tutorial/CreatingPalettes: CreatePalette@ Button[Defer[#[\[SelectionPlaceholder]]], Inherited, BaseStyle -> "Evaluate", Evaluator -> None, Appearance -> "Palette"] & /@ {crossMultiply}; ...
Here is the sqrt function with only one call to Sqrt: sqrt[x_] := Module[{sq = Sqrt[x]}, {sq, -sq}] It's about the same speed as two calls to Sqrt. But my real point was that if you want different behaviour from a function, go ahead and...