Tag: problem

EllepticPi argumet is complex. so can not plot it. How to handle this problem?

inttau[r_]=-(1/Sqrt[0.0345106153943703 - ((37.3042 - r) (-25.578 + r) (62.8822 +   r))/(3000 r)])

This is my function of r, now I integrated it w r t r

tauanalytical[r_] = Integrate[inttau[r], r]

This is what I got after integration, I got this result.

-((2.3094 Sqrt[1. + 62.1447/r] (-31.0723 + r) EllipticPi[3.,ArcSin[0.57735 Sqrt[1. + 62.1447/r]], 1.])/Sqrt[-0.965489 + 20./r + 0.000333333 r^2])

later I tried to find the numerical value of;

tauanalytical[30] // N

I got this, no the exact number , which I was expecting

-126.491 EllipticPi[3., -1.5708 + 0.153761 I, 1.]

Here the second argument of Ellepticpi comes out to be imaginary , it should be real . Please provide necessary assistance.

How can i solve php upgrade problem

I am using a plugin that works on Woocommerce.
While no error occurs on PHP 7.2 (eg 7.3) I get an error like the following in 7.2. The developer team is not helping. How can I resolve this error? It is probably caused by a foreach loop defined in the plugin. However, I am not sure how to find this cycle. I’ve been researching for about a week. I could not find a solution. I looked at a change that came with new versions of PHP. I could not see any change regarding the foreach loop. I searched for similar problem on other platforms. Unfortunately, I could not find it.

invalid argument supplied for foreach() in woocommerce/includes/wc-template-function.php on line 2735.

Problem with connect mysql databases of remote

I’m getting error with connect remote mysql database. Firstly;

1-) I use windows 10 machine and my remote server also windows 10 machine.

2-) My database at locale at remote windows machine with root.

I tried so many things but enter image description here and

ı took error picture enter image description here

Also I CREATE USER user but again ı have a problem. How can ı fixed and connect remote database

Please help me?

ODE problem using DSolve

I would like to use DSolve (or NDSolve) to verify that the solution to the ODE problem

-4(v''[t]+(2/r)v'[t])-2*v[t]*Log[v[t]]-(3+(3/2)Log[4 Pi])*v[t]==0,

with conditions $ \lim_{t\to \infty}v(t)=0$ and $ v'(0)=0$ is given by

v[t]=(4 Pi)^(-3/4)*Exp[-t^2/8].

I am able to verify this by hand, but am having trouble using Mathematica to verify it. I would like to use Mathematica to solve this differential equation, and later on modify some terms in the ODE to see how the solution changes.

Perhaps I am making a foolish mistake. I have also tried using NDSolve, but did not obtain the correct solution. I would appreciate any tips. Below you can find the picture of the error messages. Thanks for your help.

Picture of output

sol=DSolve[{-4(v''[t]+(2/r)v'[t])-2*v[t]*Log[v[t]] -(3+(3/2)Log[4 Pi])*v[t]==0,v[Infinity]==0,v'[0]==0},v[t],t] Plot[Evaluate[v[t] /. sol], {t, 0, 10}, PlotRange -> All]

Problem with plotting

So I need to plot this function:

Y(x) = 170 *sin⁡[2 *arctan [[[-x^[4] + 340*x^[3] - 35150*x^[2] + 1062500*x + 3194375]^[1/2] - 2400]/[x^[2] - 290* x + 20525]]] + 20

and i tried to do it like this

Plot    [170 * sin⁡[2 * arctan [[[-x^[4] + 340*x^[3] - 35150*x^[2] + 1062500*x + 3194375]^[1/2] - 2400]/[x^[2] - 290* x + 20525]]] + 20, {x, 0, 10}]

but i keep getting syntax error:

Syntax::sntxb: Expression cannot begin with "[[x^[4]+340x^[3]-35150x^[2]+1062500x+3194375]^[1/2]-2400]/[x^[2]-290x+20525]"

Can anyone please help?

Coloured integers: Select outcome unexpected (part of a graph based problem using coloured vertex labels)

I use the following code output and need to retrieve the position of the part containing the blue-coloured integer 4

Part 1:

List[Placed[List[       Style[3, Rule[LineColor, RGBColor[1, 0, 0]],         Rule[FrontFaceColor, RGBColor[1, 0, 0]],         Rule[BackFaceColor, RGBColor[1, 0, 0]],         Rule[GraphicsColor, RGBColor[1, 0, 0]],         Rule[FontColor, RGBColor[1, 0, 0]]],        Style[4, Rule[LineColor, RGBColor[0, 0, 1]],         Rule[FrontFaceColor, RGBColor[0, 0, 1]],         Rule[BackFaceColor, RGBColor[0, 0, 1]],         Rule[GraphicsColor, RGBColor[0, 0, 1]],         Rule[FontColor, RGBColor[0, 0, 1]]]], List[Before, After]], Placed[      List[Style[4, Rule[LineColor, RGBColor[1, 0, 0]],         Rule[FrontFaceColor, RGBColor[1, 0, 0]],         Rule[BackFaceColor, RGBColor[1, 0, 0]],         Rule[GraphicsColor, RGBColor[1, 0, 0]],         Rule[FontColor, RGBColor[1, 0, 0]]],        Style[3, Rule[LineColor, RGBColor[0, 0, 1]],         Rule[FrontFaceColor, RGBColor[0, 0, 1]],         Rule[BackFaceColor, RGBColor[0, 0, 1]],         Rule[GraphicsColor, RGBColor[0, 0, 1]],         Rule[FontColor, RGBColor[0, 0, 1]]]], List[Before, After]]]

I tried:

Part 2:

        Select[List[Placed[List[               Style[3, Rule[LineColor, RGBColor[1, 0, 0]],                 Rule[FrontFaceColor, RGBColor[1, 0, 0]],                 Rule[BackFaceColor, RGBColor[1, 0, 0]],                 Rule[GraphicsColor, RGBColor[1, 0, 0]],                 Rule[FontColor, RGBColor[1, 0, 0]]],                Style[4, Rule[LineColor, RGBColor[0, 0, 1]],                 Rule[FrontFaceColor, RGBColor[0, 0, 1]],                 Rule[BackFaceColor, RGBColor[0, 0, 1]],                 Rule[GraphicsColor, RGBColor[0, 0, 1]],                 Rule[FontColor, RGBColor[0, 0, 1]]]], List[Before, After]], Placed[              List[Style[4, Rule[LineColor, RGBColor[1, 0, 0]],                 Rule[FrontFaceColor, RGBColor[1, 0, 0]],                 Rule[BackFaceColor, RGBColor[1, 0, 0]],                 Rule[GraphicsColor, RGBColor[1, 0, 0]],                 Rule[FontColor, RGBColor[1, 0, 0]]],                Style[3, Rule[LineColor, RGBColor[0, 0, 1]],                 Rule[FrontFaceColor, RGBColor[0, 0, 1]],                 Rule[BackFaceColor, RGBColor[0, 0, 1]],                 Rule[GraphicsColor, RGBColor[0, 0, 1]],                 Rule[FontColor, RGBColor[0, 0, 1]]]], List[Before, After]]], Select[#[[1]][[2]], IntegerQ] &  == 4]

Which produces { }

However

Part 3

 a = Placed[     List[Style[3, Rule[LineColor, RGBColor[1, 0, 0]],        Rule[FrontFaceColor, RGBColor[1, 0, 0]],        Rule[BackFaceColor, RGBColor[1, 0, 0]],        Rule[GraphicsColor, RGBColor[1, 0, 0]],        Rule[FontColor, RGBColor[1, 0, 0]]],       Style[4, Rule[LineColor, RGBColor[0, 0, 1]],        Rule[FrontFaceColor, RGBColor[0, 0, 1]],        Rule[BackFaceColor, RGBColor[0, 0, 1]],        Rule[GraphicsColor, RGBColor[0, 0, 1]],        Rule[FontColor, RGBColor[0, 0, 1]]]],      List[Before, After]][[1]][[2]]  Select[a,IntegerQ]

produces 4 as expected.

Hence I would have expected Part 2 to produce the expression containing the blue label 4, i.e. the following result

Placed[List[           Style[3, Rule[LineColor, RGBColor[1, 0, 0]],             Rule[FrontFaceColor, RGBColor[1, 0, 0]],             Rule[BackFaceColor, RGBColor[1, 0, 0]],             Rule[GraphicsColor, RGBColor[1, 0, 0]],             Rule[FontColor, RGBColor[1, 0, 0]]],            Style[4, Rule[LineColor, RGBColor[0, 0, 1]],             Rule[FrontFaceColor, RGBColor[0, 0, 1]],             Rule[BackFaceColor, RGBColor[0, 0, 1]],             Rule[GraphicsColor, RGBColor[0, 0, 1]],             Rule[FontColor, RGBColor[0, 0, 1]]]], List[Before, After]]

On closer inspection I tried the following:

FullForm[Select[a, IntegerQ]]

which results in

Style[4]

However, Style[4] should not be the result of a selection for integers.

What is going on?

Problem with EnemyAi system unity keeps giving errors [duplicate]

My EnemyAi system works perfectly but for some reason when I start the game to test it unity keeps giving me errors.

Enemy Ai Script keeps giving me the NullReferenceException: Object reference not set to an instance of an object EnemyAi.Update() error inside unity about the line Vector3 lookDir = target.transform.position - transform.position;

using System.Collections; using System.Collections.Generic; using UnityEngine;  public class EnemyAi: MonoBehaviour {  public bool detected; GameObject target; public Transform enemy;  public GameObject Bullet; public Transform shootPoint;  public float shootSpeed = 10f; public float timeToShoot = 1.3f; float originalTime;  public EnemyAni Animation; public GunAni GunAnimation;  public ParticleSystem muzzleFlash;  public AudioManager Sound;  public PlayerHealth playerHealth;  void Start() {     originalTime = timeToShoot; }  public void Update() {     //makes the enemy rotate on one axis     Vector3 lookDir = target.transform.position - transform.position;      lookDir.y = 0f;      //makes enemy look at the players position     if (detected)     {         enemy.LookAt(target.transform.position, Vector3.up);         enemy.rotation = Quaternion.LookRotation(lookDir, Vector3.up);     }     if (detected == true)     {         Animation.LookPlayer = true;         GunAnimation.ShootPlayer = true;     }      if (detected == false)     {         Animation.LookPlayer = false;         GunAnimation.ShootPlayer = false;     } }

Enemy character Game Object in the unity inspector:

Enemy Character unity Inspector

Enemy vision Gameobject in the unity Inspector:

Enemy Vision unity Inspector

My organization just to show how everything is attached:

Organization in unity

The error message there are a lot because it’s talking about the other Enemy GameObejcts:

Error Messages