## mac – YouTube problems on Safari

I keep having problems using YouTube on the latest version of Safari. Videos will skip to the end after trying to watch one, making it almost impossible to watch them altogether. Ads on YouTube won’t play, or play a bunch of them in a row while skipping frames, along with a plethora of other problems. Its infuriating and I’ve tried to do everything I can to prevent this from happening like disabling my ad-blockers, clearing the cache and search history, but to no avail. I don’t know why this keeps happening, or if there even is a solution for it at all, but its infuriating.

## microsoft excel – Problems with SUMPRODUCT

I’m trying to use a formula that sums the values in one column, that match a particular criterion across various other columns.

My formula is as follows:
SUMPRODUCT(–(Chart!\$AJ\$1:\$EN\$1000=H\$2),Chart!\$T\$1:\$T\$1000)

However, I get a #VALUE! error.

The T column holds the values to be summed, whereas the criterion is to be found all over the columns AJ:EN.
Whta’s the criterion (H\$2)? It’s “OCTOBER 2020”. There are columns within the AJ:EN range that have months. The issue is that there are 15 columns with months (no, they cannot be re-arranged), and instead of using a formula for each of those columns, I wanted to make a single formula to keep things nice and tidy. The other columns have numbers and dates (which is probably why I get the value error).

The funny thing is that if I use a regular SUMIF:
SUMIF(Chart!\$AH\$1:\$EN\$1000,H\$2,Chart!T1:\$T\$1000)

I do get a result. The formula works well. However, I need to add other criteria, so I have to use either SUMIFS or SUMPRODUCT, yet I get a value error with both, even if I look up for a single criterion.

What am I doing wrong?

## class – Problems plotting Julia sets with C# using Scanner method

I’m trying to plot Julia set using oxyplot in C#. The Julia set in a function of the type f(z)=z^2+c, being c a complex coincide with the boundary of the basin of attraction of infinite (the point which that it succession of iterates converges to infinite).

In order to do this, I have created the class Complejos(Complex)

``````namespace Complejos
{

public class Complejos
{
public Complejos()
{

}

private double real;
private double imaginario;
public Complejos(double Real, double Imaginario)
{
this.Real = Real;
this.Imaginario = Imaginario;
}
public double Real { get; set; }
public double Imaginario { get; set; }

public static Complejos uno = new Complejos(1, 0);
public static Complejos menosuno = new Complejos(-1, 0);

public static double ModuloComplejo(Complejos z)
{
resultado = Math.Sqrt(Math.Pow(z.Real, 2) + Math.Pow(z.Imaginario, 2));
}

public static Complejos Julia(Complejos z, Complejos c)
{
}

{
int cont = 1;
{
cont++;
}
}

}
}

``````

The method “Julia” applies the function f(z)=z^2+c, while the method “JuliaIterada” applies the Julia method iteratively, iterada times.

For plotting the Julia set I am using two method, on one hand the iteration inverse method, which work properly. On ther other hand, the scanner method. This one.

``````using System.Collections.Generic;
using System.Text;

namespace ComplejosLibreria
{
{
Complejos.Complejos origen = new Complejos.Complejos(0, 0);
public static List<Complejos.Complejos> PasoMalla(Complejos.Complejos origen, int dividido, double altura = 0, double anchura = 0)
{
if (anchura == 0 || altura == 0)
{
anchura = altura;
}
double prueba = dividido;

double origenX = origen.Real - anchura;

double origenY = origen.Imaginario + altura;
double reinicioY = origenY;
double finalX = origenX + 2 * anchura;
double finalY = origenY - 2 * altura;
double pasoX = (finalX - origenX) / prueba;
double pasoY = (finalY - origenY) / prueba;

List<Complejos.Complejos> pasoMalla = new List<Complejos.Complejos>();

int cont = 0;
int cont1 = 0;

while (cont < dividido)
{
cont++;
origenX += pasoX;
origenY = 0;
cont1 = 0;
origenY = reinicioY;
while (cont1 < dividido)
{

Complejos.Complejos malla = new Complejos.Complejos();
origenY += pasoY;
malla.Real = origenX;
malla.Imaginario = origenY;
cont1++;
}
}

return pasoMalla;
}

public static List<Complejos.Complejos> MallaJulia3(Complejos.Complejos c, double division)
{

double paso = 6 / division;
double origenX = c.Real - 3 - paso;
double finalX = c.Real + 3;
double origenY = c.Imaginario + 3;
double finalY = c.Imaginario - 3;

List<Complejos.Complejos> Malla = new List<Complejos.Complejos>();

while (origenX < finalX)
{

origenX += paso;
origenY = c.Imaginario + 3;
while (origenY >= finalY)
{
Complejos.Complejos malla = new Complejos.Complejos();
malla.Real = origenX;
malla.Imaginario = origenY;
origenY -= paso;

}
}
return Malla;
}

{
List<Complejos.Complejos> pasoMalla = new List<Complejos.Complejos>();
pasoMalla = MallaJulia3(c, dividido);
List<Complejos.Complejos> mallaJulia = new List<Complejos.Complejos>();
foreach (Complejos.Complejos item in pasoMalla)
{

Boolean prueba;
if (prueba)

{

}
}
return mallaJulia;
}

}
}
``````

Knowing that the Julia set of a function f(z)=z^2+c, is always included in the disk with centre c and radio 3, I have created the method MallaJulia3, which take point in this disk dividing the axis x and axis Y, “division” times. Also, I firstly created the method pasoMallo, which do it the same but with a sqaure centred as the point you wish. So, using “MallaJulia3”, I created the method “MethodEscaneado2”, which applies the function “JuliaIterada” k times, and just takes the point with module(ModuloComplejos) lower than M.

In order to plot this I created this WindowsForms.

``````using System.Windows.Forms;
using OxyPlot;
using OxyPlot.WindowsForms;
using OxyPlot.Series;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;

using DocumentFormat.OpenXml.Bibliography;
using OxyPlot.Axes;
using Complejos;

using ComplejosLibreria;

namespace JuliaForms {

public partial class Form1 : Form
{
public Form1()
{
Complejos.Complejos origen = new Complejos.Complejos(0, 0);
Complejos.Complejos prueba = new Complejos.Complejos(0.285,-0.01);
Complejos.Complejos prueba1 = new Complejos.Complejos(0, -0.8);
Complejos.Complejos prueba2 = new Complejos.Complejos(-1,0);
Complejos.Complejos prueba3 = new Complejos.Complejos(-0.8,-1.6);

List<Complejos.Complejos> puntosJulia = new List<Complejos.Complejos>();

InitializeComponent();
PlotView myPlot = new PlotView();

var model = new PlotModel { Title = "ScatterSeries" };
var scatterSeries = new ScatterSeries { MarkerType = MarkerType.Circle };
var r = new Random(314);
for (int i = 0; i < puntosJulia.Count; i++)
{
var x = puntosJulia(i).Real;
var y = puntosJulia(i).Imaginario;
var size = 2.5;
var colorValue = r.Next(100, 1000);
}

model.Axes.Add(new LinearColorAxis { Position = AxisPosition.Right, Palette = OxyPalettes.Jet(200) });

myPlot.Model = model;

//Set up plot for display
myPlot.Dock = System.Windows.Forms.DockStyle.Bottom;
myPlot.Location = new System.Drawing.Point(0, 0);
myPlot.Size = new System.Drawing.Size(500, 500);
myPlot.TabIndex = 0;

}
}
} ```

So, this work sometimes, for instance using the point prueba2=-1, it plot me this image https://ibb.co/nDZkNhJ. However, sometimes does not return anything. This is due to the method "JuliaIterada", which increase all the points, but theorically it shoul not do this.

So, somebody could explain me how to fix the error.

``````

## differential equations – Problems with boundary conditions

I am new to mathematica and I have doubts with my code, I probably have errors with the boundary conditions

If you could help me I would appreciate it very much
my code is the following

``````NDSolve({(Alpha)*(D(T(x, y, t), {x, 2}) +2.5*D(T(x, y, t), {y, 2})) == D(T(x, y, t), {t, 1}),
T(x, y, 0) == to, Derivative(1, 0, 0)(T)(0, y, t) == 0,Derivative(0, 1, 0)(T)(x, 0, t) == 0, -k*D(T(L, y, t), {x, 1}) ==h*(T(L, y, t) - tam), -2.5*k*D(T(x, L, t), {x, 1}) ==h*(T(x, L, t) - tam)}, T(x, y, t), {x, y, t})
``````

I was careful with the double problem =

## 16.04 – Problems with postfix tls

and thanks for answering to my questions. I have installed postfix on Ubuntu 16.04.
I have tried to configure the main.cf and everything seems to be fina. But I check /var/log/mail.log and I see that it is sending the mails as root@hotname, when I have configured an address_verify_sender = .

Other problem I see is when I check /var/log/mail.err is
Nov 18 12:57:51 HOSTNAMEXX postfix/smtp[34733]: fatal: unknown service: smtp/tcp.

Please can you tell me what could be the problem and how to fix this?

Regards

## plotting – Manipulate and Plot of Tangent Point in Optimization Problem: Solve Problems

I want to illustrate how changes in the values of exogenous variables and parameters (T,w,(Alpha)) are changing the optimal values of two endogenous variables (f,c)=(f*,c*). The solution is with a tangency condition and a constraint.

Changes in alpha should move the U-graph along the Bcon-graph; changes in T and w change the Bcon-graph and therefore the optimal values of f and c as well as the U-graph.

``````U = f^(Alpha)*c^(1 - (Alpha))
Bcon = c - (T - f)*w
MRS = D(U, f)/D(U, c)
AbsSlpCon = D(Bcon, f)
TC = MRS - AbsSlpCon
sols = Solve({TC == 0, Bcon == 0}, {f, c})
{SuperStar(f), SuperStar(c)} = {f, c} /. Last(sols)
c1(T_, w_) := c /. Solve(c - (T - f)*w == 0, c)
c2(T_, w_, (Alpha)_) := c /. Solve(U(SuperStar(f), SuperStar(c)) == U(f, c), c)
Manipulate(Plot({c1(T, w), c2(T, w, (Alpha))}, {f, 0, 24}, PlotRange -> {25, 3000}), {T, 8, 24}, {w, 100, 500}, {(Alpha), 0, 1})
``````

Unfortunately,

1. I cannot use Bcon in line 8 to describe c1(T_,w_) but have to copy the function there to get a linear graph in the plot;

2. get no output for c2(T_, w_, (Alpha)_) in line 9, which is showing the tangent U-graph on the Bcon-graph.

“Solve::ifun: Inverse functions are being used by Solve, so some solutions may not be found; use Reduce for complete solution information.”

Any hints or suggestions?

Thanks!

## custom field – WordPress attachment problems

I use Custom Fields to set different fields I need for an interactive:

An interactive example can be like this:

In the last image there is an image attachment example, but I also attach videos and audios.

Then in my code I convert all info into a json as follows:

``````   \$attractorElements = (
"Button"      => "ip25_button",
"Title"       => "ip25_title",
"Description" => "ip25_description",
"Multimedia"  => "ip25_multimedia",
);

\$json('Content') = (
InteractiveClass::buildJsonElements("Attractor", \$attractorElements),
...
);
``````
``````public static function buildJsonElements(\$screenType, \$arrayFields) {
\$arrayElements = ();
foreach (\$arrayFields as \$key => \$value) {
\$arrayElements() = (
"ID_Element" => (
\$key => get_field(\$value, 'option')
)
);
}

return (
"ScreenType" => \$screenType,
"Elements"   => \$arrayElements
);
}
``````

This works perfectly displaying a json with all info I need (example):

``````{
"ID_Element": {
"Button 1": {
"EN": "Button 1 English",
"AR": "العربية",
"media": {
"ID": 12932,
"id": 12932,
"title": "mauritania",
"filename": "mauritania-1.jpg",
"filesize": 92850,
"alt": "",
"author": "1",
"description": "",
"caption": "",
"name": "mauritania",
"status": "inherit",
"date": "2020-10-30 12:03:22",
"modified": "2020-10-30 12:03:22",
"mime_type": "image/jpeg",
"type": "image",
"subtype": "jpeg",
"icon": "http://localhost:8080/wp-includes/images/media/default.png",
"width": 512,
"height": 512,
"sizes": {
"thumbnail-width": 150,
"thumbnail-height": 150,
"medium-width": 300,
"medium-height": 300,
"medium_large-width": 512,
"medium_large-height": 512,
"large-width": 512,
"large-height": 512,
"1536x1536-width": 512,
"1536x1536-height": 512,
"2048x2048-width": 512,
"2048x2048-height": 512
}
}
}
}
},

......
``````

My question is… What’s behind in WP that sometimes makes to display an element attached like this:

``````{
"ID_Element": {
"Button 1": {
"EN": "Button 1 English",
"AR": "العربية",
"media": {
"ID": 12932,
"id": 12932,
"title": "mauritania",
"filename": "mauritania-1.jpg",
"filesize": 92850,
"alt": "",
"author": "1",
"description": "",
"caption": "",
"name": "mauritania",
"status": "inherit",
"date": "2020-10-30 12:03:22",
"modified": "2020-10-30 12:03:22",
"mime_type": "image/jpeg",
"type": "image",
"subtype": "jpeg",
"icon": "http://localhost:8080/wp-includes/images/media/default.png",
"width": 512,
"height": 512,
"sizes": {
"thumbnail-width": 150,
"thumbnail-height": 150,
"medium-width": 300,
"medium-height": 300,
"medium_large-width": 512,
"medium_large-height": 512,
"large-width": 512,
"large-height": 512,
"1536x1536-width": 512,
"1536x1536-height": 512,
"2048x2048-width": 512,
"2048x2048-height": 512
}
}
}
}
},
``````

And other times display a simpler info (notice same image attached, but in different place)?:

`````` {
"ID_Element": {
"Button 2": {
"EN": "Button 2 English",
"AR": "العربية",
"media": 12932
}
}
},
``````

Button 1 and Button 2 have the same structure in the Custom Field.

Please, anyone that could give me a hint? I would like to display the more complete info.

## Is there a super-linear lower bound on the time complexity of all solutions of NP complete problems?

$$P ne NP$$ would imply that any polynomial is a lower bound on the time complexity of any NP complete problem.

Is some non-trivial lower bound known at all?

## troubleshooting – Friends phone keeps rebooting & other problems

A friends phone keeps rebooting, & when it does it resets their theme to the default theme. A couple times it has gotten stuck on the bootscreen requiring a battery pull to fix it. Just now after opening google photos which they have been using for a long time without any problems a popup suddenly appeared asking for permissions to access photos & wouldn’t allow access with clicking allow. The phone is a Galaxy On5.

## Prestashop Problems with Product’s Characteristic Length

I had to increase the size of the features on my Prestashop 1.7.6.8 field. To do it I’ve changed column value on ps_feature_value_lang to varchar(1024) and after modify size in override/classes/FeatureValue.php to: ‘size’ => 1024

But I have this problem: every times I save the product, when I re-enter to modify it, the features lines are double than last time.

Each save pass for example from 2 features to 4, 8, 16, 32 ect.
It have custom value strings but doesn’t have selected function.

If I try to delete I have no result, on save featured double up anyway.