15,096 reputation
12984
bio website quantdec.com
location Northeastern US
age 14
visits member for 2 years, 6 months
seen 9 hours ago

Consultant (environmental and spatial stats a specialty), expert witness, and teacher. I can be reached through (outdated but still valid) links posted on my web site.

Twitter: @WilliamAHuber // ASA-P website: http://amstatphilly.org/


Why waste time learning, when ignorance is instantaneous?

--T(iger) Hobbes.

For any complex problem there is a simple solution. And it's always wrong.

--[Mis?]attributed to H.L. Mencken by Dava Sobel, Longitude.


Dec
6
reviewed Close How to preserve graph properties under subgraph in MMA9
Dec
5
revised How to plot function over interval returned by Reduce[]
added 56 characters in body
Dec
5
revised How to plot function over interval returned by Reduce[]
Eliminated the call to `Reduce`.
Dec
5
answered How to plot function over interval returned by Reduce[]
Dec
5
comment How to plot function over interval returned by Reduce[]
Given that $x\le -1$ all satisfy your constraint (the squares are large and positive while the cubes are large and negative, whence less than $64$), how do you propose handling that infinite extent in the plot?
Dec
5
reviewed Edit How to preserve graph properties under subgraph in MMA9
Dec
5
revised How to preserve graph properties under subgraph in MMA9
added 8 characters in body
Dec
5
awarded  Investor
Dec
4
comment Small random disturbance of a flat surface
en.wikipedia.org/wiki/Stochastic_process might get you started.
Dec
4
comment Small random disturbance of a flat surface
Yes, but if that's what's intended... . I rather suspect, though, that you might want to refine your concept of a "random disturbance." You are asking for a random spatial field and those have structure. What structure are you looking for? I have described one that has a particularly simple covariance function, but (consequently) the realizations are not even continuous.
Dec
4
comment Small random disturbance of a flat surface
What is the matter with the "white noise" Plot3D[1 + RandomReal[{-0.05, 0.05}], {x, 0, 1}, {y, 0, 1}]? That would be valid as an initial condition provided it were repeatable, which can be accomplished by memoizing it: f[x_, y_] := f[x, y] = RandomReal[]; Plot3D[f[x, y], {x, 0, 1}, {y, 0, 1}]. Just watch out for uncontrolled growth in RAM used by f!
Dec
4
revised How do you pattern match a DataDistribution
added 23 characters in body
Dec
4
comment NDSolve and {C, K, Slot} and other built-ins as a variable name
@Oleksandr That's right, but MMA differs from C by having many thousands of "reserved words" (although, arguably, they are all identified by one simple rule), by allowing them to be overloaded--which is not the case for a true reserved word--and, as exemplified by this question, by not issuing informative error messages when such words are misused. (This is not to defend the coding practice exhibited here, though.)
Dec
4
awarded  Custodian
Dec
4
reviewed Leave Closed Inputting abbreviated units
Dec
4
reviewed Looks OK Preserving labels when using graph functions
Dec
4
reviewed Leave Open How to deal with WebServices error “any is not supported in sequence”?
Nov
30
comment Finding the intersection of two date lists
In some ways it's good that converting strings to dates is the rate-determining step: that means we shouldn't be too concerned about optimizing the join itself, and that gives us the flexibility to craft code that executes correctly in most circumstances. It still looks like a good idea to do the string-to-date conversion, despite the time it takes, because that avoids subtle problems created by potential failures to match two different strings that otherwise represent the same date. Alternatively: do your database operations with a database management system!
Nov
29
answered Finding the intersection of two date lists
Nov
29
comment Computation of parametric integral
Are you sure you didn't mean to integrate (g(u^(g - 1)))/(1 + u^g) instead? It would be a whole lot easier ... :-).