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comment Factor out certain terms using Modulus but Mathematica requires that the modulus be an integer
What is the anticipated result?
Apr
23
comment numerically solving
[I have nothing against square brackets.]
Apr
23
comment numerically solving
You can use FindRoot to solve once given specific values for a.
Apr
22
comment How do I find the nearest city out of a list of cities?
Here we create a NearestFunction. In[52]:= nf = Nearest[cities]; Now use it to find the two closest ones to the fourth entry. Rest[nf[cities[[4]], 3]] Out[53]= {GeoPosition[{18.98, 73.27}], GeoPosition[{17.92, 73.67}]}
Apr
22
comment How do I find the nearest city out of a list of cities?
Use GeoPosition on your list of cities as input to Nearest, to get a NearestFunction. You can then apply that to individual cities to get neighbors within some radius.
Apr
22
answered Limits with assumptions
Apr
22
comment Approaches to solving non-linear systems of equation with assumptions
That's the sort of thing documentation is really good for (and this forum is not.
Apr
21
comment Implementing the Golden Section Rule
What is the bad behavior? What behavior are you expecting? What is the result you intend to return (if any)?
Apr
21
comment Trying to write my own Greedy/ Nearest Neighbor Algorithm
What have you tried?
Apr
20
comment Approaches to solving non-linear systems of equation with assumptions
This might give a result more to your liking (maybe). equations = {(r - rp) x + 4 d1 x^3 + 4 d12 x y^2 == 0, (r + rp) y + 4 d2 y^3 + 4 d12 y x^2 == 0, Element[{r, rp}, Reals], d1 > 0, d2 > 0, d12 > 0, d1 d2 > d12^2}; result = Reduce[equations, {x, y}, Reals]
Apr
20
comment Faster variant of Reduce for finding zeros of holomorphic functions in a region
I think numeric integration is sometimes used by Reduce although I am not absolutely certain it is used in this example. That of course does not address the speed issue under consideration. One thing I will suggest is that you post an explicit example (no symbolic a[n], that is). That way readers might have something to test against.
Apr
20
comment Faster variant of Reduce for finding zeros of holomorphic functions in a region
Is the variable s? If so, this seems like it might be difficult since it's not polynomial.
Apr
19
comment Improving Performance - Finding Polynomial Roots
(3) As for faster generation, could use this: Timing[maxDeg = 12; polys = 1 + Flatten[Outer[List, Apply[Sequence, Table[{1, 0, -1}, {maxDeg}]]], maxDeg - 1].x^Range[maxDeg];]
Apr
19
comment Improving Performance - Finding Polynomial Roots
(2) You are also doing too much work by a factor of 2. You can insist that the constant term be 1 in p[x] because case of -1 will show up as the negative version of same (that is, -p[x]`). (This was also noted in a response by @2012rcampion.)
Apr
19
comment Improving Performance - Finding Polynomial Roots
(1) Have you checked the source of the bottleneck? I ask because the quadratic complexity of the mode of generating them leads me to suspect that that's where the main problem lies. At maxDeg=9 it took 28 seconds on my machine. For maxDeg=10 it took around 5 minutes. I expect roughly a factor of 9 for each increment (factor of 3 growth, squared due to the AppendTo complexity).
Apr
17
revised Empty Blank regression in v10.1
edited tags
Apr
17
comment Finding the period of an array of integers
For the case of missing or corrupted values, there is some discussion in this MathGroup thread
Apr
16
comment How to plot the graph of the equation F[x,y]=0 if y is real number, x is complex?
Also on Wolfram Community
Apr
15
comment Is there a function or option to collect factors under one radical sign?
I get nervous whenever factions start to collect under one radical.
Apr
15
answered Checking if a symbolic matrix is positive semi-definite