text stringlengths 64 27.2k | meta dict |
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Q:
Fit a function to data so that fit is always equal or less than the data
I have a set of measurement data and I try to fit there a function (a Exp[b x] + c Exp[d x] - o). I have two problems:
The fit function does not converge nor after $500$ iterations.
The fit function always has to be equal or less than the da... | {
"pile_set_name": "StackExchange"
} |
Q:
Filter RDD based on some criteria
I have one RDD like below -
[[u'100=NO', u'101=OR', u'102=-0.00955461556684', u'103=0.799738137456', u'104=-0.619426440691', u'105=-0.505799761741', u'106=1.06018348173', u'107=-0.203731351216', u'108=0.242253668965', u'109=20170411', u'110=14:47:54'], [u'100=NO', u'101=OR', u'10... | {
"pile_set_name": "StackExchange"
} |
Q:
How to do good surface fitting in Mathematica?
I would like to fit a 3D surface in Mathematica, and I can do a rough fitting using the following code:
pcA = {0.1, 1, 2, 3, 4, 5};
b0 = {0, 0.1, 0.2, 0.38, 2, 8};
data = {{0, 0}, {0, 0}, {0, 0}, {0, 0}, {0, 0}, {0,
0}, {-0.20581267, -0.20537408}, {-84.63568022, ... | {
"pile_set_name": "StackExchange"
} |
Q:
Forcing FindRoot to return only real solutions
FindRoot documentation reports that if the equation and the initial point are reals, the solutions are searched in the real domain.
However, in the following case I get a complex solution
FindRoot[eq, {h, 1.7}]
{h -> -0.990042 - 0.689686 I}
Same for
Assuming[Reals... | {
"pile_set_name": "StackExchange"
} |
Q:
What's this text encoding?
I used Python's imaplib to pull mail from a gmail account... but I got an email with this confusing text body:
> RGF0ZSBldCBoZXVyZTogICAgICAgICAgICAgICAgICAgICAgICAgICAyMi8wOC8yMDEwIDE0
> OjMzOjAzIEdNVCBVbmtub3duDQpQcsOpbm9tOiAgICAgICAgICAgICAgICAgICAgICAgICAg
> ICAgICAgICAgamFjaW50bw0KT... | {
"pile_set_name": "StackExchange"
} |
Q:
Keeping determine digits in Append to process
The end of my code is written as below. Ignoring the inefficient role of Append, I want to have very simple set of values as for example:
{0.70, 0.091, 0.3032},{0.70, 0.094, 0.2933},{0.70, 0.097, 0.2840}.....
But when I copy and paste whole (below code) in another not... | {
"pile_set_name": "StackExchange"
} |
Q:
Prove that any linear functional on $\mathbb{R^{n}}$ with the Euclidean norm is bounded
I'm not sure how to prove this without just using the fact that is equivalent to say that a linear functional is continous.
A:
For
$\vec v \in \Bbb R^n, \tag 1$
we may write
$\vec v = \displaystyle \sum_1^n v_i \vec e_i, \tag... | {
"pile_set_name": "StackExchange"
} |
Q:
Python: get the most maximum values from dictionary
I have a dictionary
{u'__': 2, u'\u0441\u0442\u0440\u0430\u043d\u0438\u0446\u0430': 1, u'\u041f\u043e\u0447\u0435\u043c\u0443': 1, u'\u041d\u0430\u043c': 1, u'\u043e\u0434\u0438\u043d': 1, u'\u0441\u043e\u0432\u0435\u0442\u0430\u043c\u0438': 1, u'\u041f\u0440\u0... | {
"pile_set_name": "StackExchange"
} |
Q:
reduced image quality / sharpness when texture has opacity / alpha / transparency
The output of Graphics3D looks blunt (polygon borders, arrow) when a polygon primitive is present in the scene with texture that has opacity channel. Also it seems that different kind of texture filtering is applied. I'm on Win10 and... | {
"pile_set_name": "StackExchange"
} |
Q:
What does this suspicious and likely malicious code do?
A random user added this text as his name in a web form. I suppose his idea was to somehow inject Javascript into a dynamic page. How should this code be interpreted? (What does it do?)
<script LANGUAGE="JavaScript">
function Decode() {
var temp = "",
... | {
"pile_set_name": "StackExchange"
} |
Q:
Why doesn't my d3.js line chart work?
I'm currently learning d3.js, and as a task I am trying to build a line chart using a custom data source. For some reason, I can't get the line generator to work, and it seems like it can't create the d attribute for the path element. I don't seem to get any error messages eit... | {
"pile_set_name": "StackExchange"
} |
Q:
Calculating the inelastic quasiparticle lifetime of a screened quantum fluid
I've been studying "Lifetime of a quasiparticle in an electron liquid", by Qian and Vignale. Much of it makes sense, but there is a detail in the calculation of the exchange term that doesn't make sense to me. Eqn. 23 gives
$$\frac{2\pi m... | {
"pile_set_name": "StackExchange"
} |
Q:
Three Dimensional Plot of Numerical Integral with Delta Function
I want to plot the definite integral of the following function
Integrand[p_, Q2_, ν_, θ_] := p^2/(M^2 (M - 2*E3[p])^2)
1/(E3[p] E4[p, Q2, ν, θ]) 1/D[f[p, Q2, ν, θ], p]
DiracDelta[p - p3zero1[Q2, ν, θ]]+p^2/(M^2 (M - 2*E3[p])^2)
1/(... | {
"pile_set_name": "StackExchange"
} |
Q:
Compare 4 columns in two files; and output the line for unique combination (from first file) and line for duplicate combination (from second file)
I have two tab separated values file, say
File1.txt
chr1 894573 rs13303010 GG
chr2 18674 rs10195681 **CC**
chr3 104972 rs990284 AA <--- Unique Line
... | {
"pile_set_name": "StackExchange"
} |
Q:
Evaluating $\sum_{r=0}^{10}\frac{\binom{10}{r}}{\binom{50}{30+r}}$
The question is to evaluate $$\sum_{r=0}^{10}\frac{\binom{10}{r}}{\binom{50}{30+r}}$$I tried rewriting the expression as $$\sum_{r=0}^{10}\frac{\binom{20-r}{10}\binom{30+r}{r}}{\binom{50}{30}\binom{20}{10}}$$ I am facing trouble on how to further s... | {
"pile_set_name": "StackExchange"
} |
Q:
Showing a system is always controllable?
I need to show that the following system is always controllable:
\begin{align}A &= \begin{bmatrix}
-\alpha_1I_{k\times k}& -\alpha_2I_{k\times k}& \cdots &-\alpha_{n-1}I_{k\times k}&-\alpha_nI_{k\times k}\\
I_{k\times k}&0_{k\times k}&\cdots&0_{k\times k}&0_{k\times k}\\
0_... | {
"pile_set_name": "StackExchange"
} |
Q:
Inequality for moments of sums
Suppose the random variables $X_i$ are independent and satisfy $E[X_i] = 0$. Then the following inequality holds:
$$E\left[\left(\sum \limits_{i = 1}^n X_i\right)^4\right] = \sum \limits_{i = 1}^n E[X_i^4] + 3\sum \limits_{i \ne j} E[X_i^2X_j^2] \le 3\left(\sum \limits_{i = 1}^n E[X_... | {
"pile_set_name": "StackExchange"
} |
Q:
$X$ a normal r.v , calculating $\mathbb{E}(e^{\lambda X})$
$X\sim { \mathcal{N}( \mu , \sigma^2) } $
a normal r.v, $Y = \frac{X-\mu}{\sigma} $
The solution says $\mathbb{E}(e^{\lambda X})= \mathbb{E}(e^{\sigma \lambda Y}) e^{\lambda \mu} = e^{\sigma^2 \lambda^2 + \lambda \mu} $
But what I find is :
$\mathbb{E}(e... | {
"pile_set_name": "StackExchange"
} |
Q:
Finding extremums of Abs[complex function]
We have a function same as
f[x_]=Cos[x] Cos[2 x] + I Sin[x] Sin[2 x]
The final objective is to find all extremums of Abs[f[x]] in [0,2 pi]. But in the first step there is a problem because Abs[x + I y] != Sqrt[x^2+y^2] except x and y be numeric. Also, in any trick Funct... | {
"pile_set_name": "StackExchange"
} |
Q:
CustomLoading in android ( error : expected resource of type drawable )
Can somebody recommend the best way to CustomLoading in android Project.
i using this post.
my code :
_readNewsAsyncTaskManager = new ReadNewsAsyncTaskManager();
_loadigIcon.setImageResource(R.anim.loading_animation);// Error*
loadingViewAnim... | {
"pile_set_name": "StackExchange"
} |
Q:
Regex Extract [Jmeter]
To make this short: I have a json response, and I need to extract some parameters from it. (Using jmeter, Regular Expression Extractor)
json response:
{"success":true,"data":[{"valId":null,"oclOclIdIndexType":null,"yearno":null,"docId":274253,"iconCls":null,"versionNo":1,"parentId":null,"id... | {
"pile_set_name": "StackExchange"
} |
Q:
could someone tell me what wrong with my number to word code?
Here's the class definition I'm using:
<?php
class number_word {
private $word_array = array(1=>"One",2=>"Two",3=>"Three",4=>"Four",5=>"Five",6=>"Six",7=>"Seven",8=>"Eight",9=>"Nine",10=>"Ten",11=>"Eleven",12=>"Twelve",13=>"Thirteen",14=>"Fourteen",... | {
"pile_set_name": "StackExchange"
} |
Q:
How to remove non alphanumeric characters and space, but keep foreign language in JavaScript
I want to remove signs like:
!@#$%^&*()_+`-=[]\|{};':",./<>?。，‘“”’；【】『』
and many more.
But ensuring all the foreign characters are kept, such as Chinese, French, Greece, etc.
In Ruby, I'm able to do it with regex
/[^\p{... | {
"pile_set_name": "StackExchange"
} |
Q:
Remove part between two patterns in bash
Let's say I have a huge file with this:
(Ano_gla|EOG091B00FI:0.21327484,Tri_cas|EOG091B00FI:0.14561670,((Tri_bro|EOG091B00FI:0.00523450,Tri_jap|EOG091B00FI:0.01261030)1.00
0000:0.26780267,(((((Orm_nit|EOG091B00FI:0.00243200,Orm_pom|EOG091B00FI:0.00914980)1.000000:0.08747204... | {
"pile_set_name": "StackExchange"
} |
Q:
Use Rao-Blackwell Theorem on $N(0,\sigma^2)$ distribution
Suppose that $X_1,X_2,...,X_n$ is a random sample from a normal distribution, $X_i\sim N(0,\sigma^2)$.
Find the UMVUE of $\phi(\sigma)=2\mathbb{P}_{\sigma}(X>c)$ where $c>0$.
My try: $Y=\mathbb{1}_{\{|X_1| >c\}}$ be unbiased estimator of $\phi(\sigma)$.
I... | {
"pile_set_name": "StackExchange"
} |
Q:
Reproduce diagram relating different continuity properties
I want to reproduce the following diagram as one of the implications is wrong and I want to add some and see if I can manage without having certain terms twice in the diagram (i.e. "stetig").
I tried using Tikz-cd.
My question: How can I define globally t... | {
"pile_set_name": "StackExchange"
} |
Q:
How to evaluate $\int \frac{x dx}{x^4 + 6x^2 + 5}$?
$$\int \frac{x dx}{x^4 + 6x^2 + 5}$$
How to evaluate this integral ?
A:
$$\int \frac { xdx }{ x^{ 4 }+6x^{ 2 }+5 } =\frac { 1 }{ 2 } \int { \frac { d{ x }^{ 2 } }{ { \left( { x }^{ 2 }+3 \right) }^{ 2 }-4 } } =\frac { 1 }{ 2 } \left[ \int { \frac { d{ x }^{ ... | {
"pile_set_name": "StackExchange"
} |
Q:
How to wrap lists with proper indentation when using org-indent-mode?
In Org-mode I can get headlines wrap with proper indentation by using org-indent-mode. How can I do the same for lists, that is, how can I make it so that lists in Org-mode wrap with proper indentation?
If I insert
* Very very very very very ve... | {
"pile_set_name": "StackExchange"
} |
Q:
Seasonal weather data
I have some twenty years of weather data with daily average temperature. I would like to make a histogram with aggregated monthly average for the whole period. I tried to do something like this https://www.wolfram.com/language/11/time-series-processing/trends-and-seasonalities.html?product=la... | {
"pile_set_name": "StackExchange"
} |
Q:
Inexact coefficient message showing up without any inexact coefficients
I have seen this message (Solve was unable to solve the system with inexact coefficients. The answer was obtained by solving a corresponding exact system and numericizing the result.) appear when trying to find when a function equals zero. How... | {
"pile_set_name": "StackExchange"
} |
Q:
Invariance of Lagrangian under rotations in a constant magnetic field
The Lagrangian for the motion of a particle with mass $m$ and charge $q$ in a constant magnetic field $B$ is given by $$\mathcal{L}(x,v)=\frac{m}{2}\left|v\right|^2-\frac{q}{2c}\left(v\cdot[x\times B]\right).$$
Show that rotations around the $B$... | {
"pile_set_name": "StackExchange"
} |
Q:
Подправить простую регулярку
Есть регулярка в обработчике бб-кодов. Такая строка:
$text = preg_replace_callback('#\[img=([^\]]+?)\]http://([^\] \?]+?)\[/img\]#si',
Проблема в том, что не поддерживаются картинки с протоколом https://
Делаю так:
$text = preg_replace_callback('#\[img=([^\]]+?)\]http(s*)://([^\] \?... | {
"pile_set_name": "StackExchange"
} |
Q:
Text at the end of the table
I am experiencing another problem with my table I would like to include a long note at the end of the table.
The code I wrote is:
\documentclass{article}
\usepackage{rotating}
\usepackage{xcolor}
\renewcommand{\baselinestretch}{1.3}
\setlength{\topmargin}{0cm}
\setlength{\oddsidemargi... | {
"pile_set_name": "StackExchange"
} |
Q:
Putting an object/dynamic as a DataGridView
Well I got a JSON String after decrypting which looks like
"{\"HardwareInformation\":{\"NumberOfProcessors\":8,\"PageSize\":4096,\"ProcessorType\":586,\"ProcessorTypeText\":\"]\",\"ActiveProcessorMask\":255},\"SystemInformation\":{\"ComputerName\":\"PD-AT-23006\",\"User... | {
"pile_set_name": "StackExchange"
} |
Q:
Unable to parse a value inside json object in javascript
I am trying to parse a value which is residing inside a json object . Below is the response from my API call.
var responseData = {
"statusCode": 200,
"body": "{\"Errors\":\"\",\"Message\":null,\"OrgID\":0,\"Output\":\"{\\\"AllUserDetails\\\":{\\\"UserDet... | {
"pile_set_name": "StackExchange"
} |
Q:
Changing something from iterating over a numpy array to vectorization
I am trying to speed up the piece of code below by vectorization:
[rows,cols] = flow_direction_np.shape
elevation_gain = np.zeros((rows,cols), np.float)
for [i, j], flow in np.ndenumerate(flow_direction_np):
try:
if flow == 32:
... | {
"pile_set_name": "StackExchange"
} |
Q:
More than 15 KML-layers wont be visible on Google Maps API-based page
I have this strange issue: I have to generate many KML-layers from separate KML-files to a single map window. The amounts vary between like a couple and less than fifty. At the moment my code is producing just correct behaviour when I'm giving i... | {
"pile_set_name": "StackExchange"
} |
Q:
How to sum a cell in Matlab
I am a new learner in Matlab and now want to add up a cell of column elements in Matlab, somehow "sum" function didn't work and it shows "Undefined function 'sum' for input arguments of type 'cell'", is there anyone know how to do it? MANY THANKS!:)
my data is like this:
'218148'
'10685... | {
"pile_set_name": "StackExchange"
} |
Q:
ggplot2 geom_bar plot Labels fall outside plot
Question
I'm trying to locate labels of a bar plot using ggplot2 over the bars.
The problem I get is that the labels fall "outside" the plot.
Load packages
library(ggplot2)
library(plyr)
library(reshape2)
Barplot
df_1 <- data.frame(PROV = c("BUENOS AIRES", "BUENOS A... | {
"pile_set_name": "StackExchange"
} |
Q:
SQL syntax error - check the manual
<?php function createLead($CuFirst, $CuLast, $COBool, $COFirst, $COLast, $CuAddrs1,
$CuAddrs2, $CuCity, $CuZip, $CuEmail, $CuDphone, $CuHphone, $CuCphone, $BuildYr, $HoAge, $NoWindows,
$NoWindowQuote, $WindowType1, $WindowType2, $WindowType3, $WindowType4, $G... | {
"pile_set_name": "StackExchange"
} |
Q:
Limit Of a Sequence involving square-Root
How can I use the fact that $\sqrt[n] {n} \to 1 $ in order to calculate the limit of the sequence:
$ \sqrt[n] {9n^2 + 30n + 17} $ ?
Thanks
A:
Hint:
$$ \sqrt[n] {n}\leq \sqrt[n] {9n^2 + 30n + 17}\leq \sqrt[n] {56n^2}. $$
| {
"pile_set_name": "StackExchange"
} |
Q:
$\mathbb{Z}[T]$-module and extension
I consider the structure of $\mathbb{Z}[T]$-module on $\mathbb{Z}$ given by the multiplication $P \times a := P(0) \times a$.
Now i consider a morphism of ring $\phi : \mathbb{Z}[T] \to R$, that give a structure of $\mathbb{Z}[T]$-module on $R$, i denote by $t := \phi(T) \in R... | {
"pile_set_name": "StackExchange"
} |
Q:
Greatest value of shortest distance between axis of x and normal to ellipsoid
Show that greatest value of shortest distance between axis of $x$ and a normal to ellipsoid is $$b-c$$
or in other words show that the maximum distance of all the normals to the ellipsoid is $b-c$
$$\frac{x^2}{a^2}+\frac{y^2}{b^2}+\frac{... | {
"pile_set_name": "StackExchange"
} |
Q:
Approximating a Continued Fraction
From a paper I was reading, If:
$$w=\frac {1}{3}\left\{ \frac {-\dfrac {3}{16}\lambda^2}{1}+\frac {-\dfrac {3}{16}\lambda^2}{1}+\frac {-\dfrac {3}{16}\lambda^2}{1}+\frac {-\dfrac {11}{48}\lambda^2}{1}+\cdots\right\},$$
(which is a continued fraction) and "each numerator above is ... | {
"pile_set_name": "StackExchange"
} |
Q:
$V=\{A\in M_n(\mathbb Q): \operatorname{tr}A=0\}$, Prove that $V\oplus \operatorname{Span}\{I_n\}=M_n(\mathbb Q)$
Q: Let $V=\{A\in M_n(\mathbb Q): \operatorname{tr}A=0\}$.
Prove that $V\oplus \operatorname{Span}\{I_n\}=M_n(\mathbb Q)$
Since $\dim(V\cap \operatorname{Span}\{I_n\})=0$, $\dim(\operatorname{Span}\{I_... | {
"pile_set_name": "StackExchange"
} |
Q:
Determine if $\sum_{k=1}^{\infty}\frac{\ln{k}}{k\sqrt{k}}$ converges/diverges.
I'm trying to use the theorem that:
If $$\lim_{k\rightarrow\infty}\frac{a_k}{b_k}=A,$$ then the positive
series $\sum_{k=1}^{\infty}a_k$ and $\sum_{k=1}^{\infty}a_k$ are both
either convergent or divergent.
But no matter what con... | {
"pile_set_name": "StackExchange"
} |
Q:
limits of function without using L'Hopital's Rule $\mathop {\lim }\limits_{x \to 1} \frac{{x - 1 - \ln x}}{{x\ln x+ 1 - x}} = 1$
Good morning.
I want to show that without L'Hopital's rule :
$\mathop {\lim }\limits_{x \to 1} \frac{{x - 1 - \ln x}}{{x\ln x + 1 - x}} = 1$
I did the steps
$
\begin{array}{l}
\mathop ... | {
"pile_set_name": "StackExchange"
} |
Q:
Laplace transform of $\cosh(t)$ from first principles: How to deal with infinities?
I'm trying to find the Laplace transform of $\cosh(t)$ from first principles. My work is as follows:
$$\begin{align} \mathcal{L}\{\cosh(t)\} &= \int_0^\infty e^{-st} \cosh(t) \ dt \\ &= \dfrac{1}{2} \int_0^\infty e^{-st} \left( \df... | {
"pile_set_name": "StackExchange"
} |
Q:
Pattern quote creates excessive amount of \Q and \E
While replacing the string X with any pattern from ArrayList S, the new message N, produces an excessive amount of regex quotes, \Q and \E.
Is their some kind of way to break the loop once it reads through the message or implement some kind of count down to preve... | {
"pile_set_name": "StackExchange"
} |
Q:
Different determinants on 2 different computers
Is there any way to force Det to do itself in a certain way?
I've been running the same notebook on 2 differents computer, one MacOSX Lion and one W7 (both 32bit) with Mathematica 8.0.0.0 on the two of them, and we don't get the same Det expression and Solve[Det[F[x]... | {
"pile_set_name": "StackExchange"
} |
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