Differential equations – How do you solve the eigenvalues ​​of this 2nd order ODE?

I have tried to solve the eigenvalue problem of 2nd order ODE $$[b^2(k-2)y(3+(k-2)y)-2b(k-2)(1+2ky)+4k^2]f (y) – 3b (3by-2) f? (y) – (3by-2) ^ 2f? # (Y) $$ With NDEigenwert, The limit is infinite, or at least very far, to obtain a convergent solution, and here I use only an empirical one ycutoff,

The resulting eigenvalues ​​seem to be quite unstable against tuning the values MeshOptions, Unfortunately, I do not know if there is an analytical solution. So I hope there is a way or other ways to solve the problem.

k = 0; b = 2; ycutoff = 15.0; Nless = 50;
lhs = (b ^ 2 (-2 + k) y (3 + (-2 + k) y) -2b (-2 + k) (1 + 2 k y) + 4 k ^ 2) f[y] 
      - (-2 + 3 by) (3 bD)[f[f[f[f[y]y]+ (-2 + 3 by y) D[f[f[f[f[y], {y, 2}]);
bc = DirichletCondition[f[f[f[f[y] == 0, true];
{vals, funcs} =
NDEigensystem[{F}lhsbc[{F}lhsbc[{lhsbc}f[{lhsbc}f[y]{y, -ycutoff, ycutoff}, Nless,
Method -> {"PDEDiscretization" -> {"FiniteElement", {"MeshOptions"
-> {"MaxCellMeasure" -> 0.01, "MeshOrder" -> 2}}}}];

Not sure if related. The equation does not seem to have a singularity, but the solutions are shown (Section of the first ten) seem to be more oscillating $ y = 0 $,
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To sort a string in Python in the order of AaB instead of ABa

I am trying to sort a string (to create a genotype for a playing field).
My current implementation is:

unsorted_genotype = & # 39; ABaB & # 39;
sorted_genotype = sorted (list (unsorted_genotype))
sorted_string = & # 39; & # 39; .join (sort__genotype)

It gives out

& # 39; ABBA & # 39;

However, I would want and expect:

& # 39; # 39 & AaBB;

How can I change or fix this?

How do I change the order of videos on YouTube in a playlist I've created?

Suppose I created a playlist on YouTube and added 50 videos. Now I want to exchange Video 30 and Video 31. Is there an easy way?

There seems to be a way, but very complicated: you can move a video up or down so you can move Video 30 up and Video 31 up. Now video 31 is in front of video 30. Now move the previous video # 29 one after another on video # 1 "up", and the order will be set in the order you want, but it's really complicated.

Plotting – Questions about Bezier curves of higher order

I can produce the same Bezier curve with my own code as the curve generated by the BezierCurve function of Mathematica, but if I increased the order of the curve, the graph I created seems to be different from that generated by Mathematica.

I did it according to the definition of the Bezier curve, I do not know why. Can anyone explain to me?

point generation[k_] : = RandomReal[10, {k, 2}];
Parametrierkriterien[n_, x_,l_List]: = (Binomial[n-1,Prepend[Range[n-1]0]]table[x^i (1-x)^(n-1-i),{i,0,n-1}]) .l;
a = points generation[5];
cc = parameter values[5, x, a];
ParametricPlot[{cc[[1]]cc[[2]]}, {x, 0, 1}, AxesOrigin -> {0, 0}];
graphic[BezierCurve[a], Axes -> Right, AxesOrigin -> {0, 0}]

2013 – REST API: I want to show all items with a certain value first, even if they are not arranged in alphabetical order (asc and desc do not work).

I just threw my options down

I think the simpler option would be to create a calculated column in SharePoint based on the Status field and specifying the order you want.

New item = 0, pending = 1

Now use your existing REST API query to display ASC in the calculated column


Try using the SharePoint REST API with CAML queries to do the grouping, and then let Javascript process the data and display it accordingly.


Send and display in separate REST API call for each status.

postgresql – paginate correct order by ambiguous values?

How can I properly scroll by sorting by a column that may contain repeated values? I called a table poststhat contains a column that contains the number of likes of a particular item num_likesand I want to order by num_likes DESC, However, the picture below shows a problem that I come across: The new line inserted between the two pages causes repeated data to be retrieved.

This link explains the problem and gives the solution Keyset paginationbut from what I've seen, this only works if the column after which the rows are sorted is unique, How would I do that if this is not the case?

New line problem pagination