Online Mathematica, pros and cons, linear algebra problem

I apologize in advance if this question is irrelevant to this website.

I would like to use Mathematica to solve a system of linear equations with lots of unknowns(729 unknowns), the unknowns are tensor components of curvature tensors arising from a differential geometry problem.

I would like to buy Mathematica for this purpose and I have to decide between buying it online or installing the desktop version on a PC. I m thinking of buying the online version. I have the following questions:

  1. What are the advantages and disadvantages of the desktop version over the online version ? For example, are there mathematical or programming functionalities which are available only on the desktop version and not in the online version ?

  2. I assume that if I buy the online version, then I will get a username and a password to access an online version of mathematica from any computer. (Just like how one can type latex on from an online account using any PC). Is my assumption correct ?

3)Does Mathematica provide a user friendly way for solving linear simultaneous equations with lots of unknowns ? Let me elaborate with an example: Say I want to solve the simultaneous equations $ x=2y+a, y-3x=7x+2$ for $ x,y$ . I would like a software where I can just type: $ x=2y+a, y-3x=7x+2$ and ask the software to solve for $ x,y$ and just give me the solution symbolically in terms of parameter $ a$ instead of me having to rearrange terms so that the equations become $ x-2y=a, y-10x=2$ and then write it in matrix form, then ask it to make a matrix inversion. The difference I am talking about might seem silly in this example but it will not be silly in my original problem where I have 700 unknowns. If this feature exists in Mathematica, it will save me a lot of time.

Thank you,

Facing problem to implement SSL redirect

I want to add a checkbox button for automatically redirect to HTTPS if SSL is present. the process I added like below:

this is form area:

<form action="options.php" method="POST" id="<?php echo esc_attr( $  data['slug'] ); ?>_options">             <?php settings_fields( $  data['slug'] ); ?>             <?php $  this->render_form_sections(); ?>             <?php $  this->render_hidden_fields(); ?>             <input type="submit" class="wpr-button" id="wpr-options-submit" value="<?php echo esc_attr( $  data['btn_submit_text'] ); ?>"> </form>          

added new field in the form:

$  this->settings->add_settings_fields(         [                          'ssl_redirect'       => [                 'type'              => 'checkbox',                 'label'             => __( 'Enable SSL Redirect', 'rocket' ),                 'section'           => 'enable_ssl_section',                 'page'              => 'hub',                 'default'           => 0,                 'sanitize_callback' => 'sanitize_checkbox',             ], 

added this:

if ( $  wp_rocket_requirement_checks->check() ) {      require WP_ROCKET_INC_PATH . 'main.php';     require WP_ROCKET_INC_PATH . 'custom.php';   } 

this custom.php is added for making action function after checkbox is true state. this is my custom.php

<?PHP   defined( 'ABSPATH' ) || exit;    ?> 

I want to add this function code in cutom.php how to add this and how form action will perform please solve this.

function enable_ssl_redirect() {     if ( isset( $  _SERVER['HTTPS'] ) ) {         if ( 'on' === strtolower( $  _SERVER['HTTPS'] && strpos( home_url(), 'https' ) == false ) ) {         wp_redirect(str_replace( 'http', 'https', home_url() ));     }      if ( '1' == $  _SERVER['HTTPS'] ) {         wp_redirect(home_url());     } } elseif ( isset( $  _SERVER['SERVER_PORT'] ) && ( '443' == $  _SERVER['SERVER_PORT'] ) ) {      wp_redirect(home_url()); }  return false; } 

Problem with using Monitor with ParallelTable

I am trying to run some simulation with ParrallelTable with the following code

SetSharedVariable[simCount]; simCount = 0; Monitor[data =     ParallelTable[simCount += 1; longSimulation[],     {i, 1, 100}], simCount]; 

I learned to do this from this question. However, I noticed that this code shows the number of simCount jumps to 100 very quickly, and then stop there for a long time to actually do the job.

I am using Mathematica 12.1. I suspect the way Monitor and ParallelTable interact has changed a bit. How can I get this to work again?

Mathematica not computing Matrix problem, just returning multiplication expression

I’m doing some very simple matrix operations in Mathematica, but for some reason, the last operation I’m trying to evaluate is not returning the actual product, just shows the symbolic multiplication.

P = { {1, 2}, {3, 4}} /10;  im = {{1},{1}} in = {{1},{1}}  A = ArrayFlatten[ { {KroneckerProduct[in\[Transpose], IdentityMatrix[2]]}, {KroneckerProduct[IdentityMatrix[2], im\[Transpose]]} } ]  p = Flatten[P] // MatrixForm  A.p 

This last operation, $ A\cdot p$ is returning the following:

enter image description here

Why is that so?

Problem with wp_query in Safari

The Query for my custom post type works well for most browsers, but there’s a problem loading the images in Safari for MAC (not iphone), the may appear at first sight but they dissapear constantly


I have modified the Query several times to reduce the quantity of elements charging (the problem seems to be worse when there are more custom post types being shown).

Canonical solution of a scoping problem

Scoping is a recurrent issue on this forum.

Yet, I stumble again and again at the same thing. Googling over this site does not quickly bring a solution. Two reasons:

  1. There are many low quality answers such as this one (and I can elaborate on this, if needed).
  2. There are many very good answers (this and this), but they are too long.

Sometimes I just want to learn by examples, not by reading many pages of dry theory. Therefore I would like to ask this question again even at risk being downvoted or the question being closed.

Consider this code

ClearAll[g,i,list];  list=Range[3] g[l_]:=Module[{i},l/.{i_->2i}]  g[list] i=5 g[list]  Out[2]= {1,2,3} Out[4]= {2,4,6} Out[5]= 5 Out[6]= 10 

Or a very similar one

ClearAll[g,i,list];  list=Range[3] g[l_]:=Cases[l,i_->2i]  g[list] i=5 g[list]  Out[8]= {1,2,3} Out[10]= {2,4,6} Out[11]= 5 Out[12]= {10,10,10} 

It is clear to me that setting the global variable i interferes with the function definition. I would like to know what is the canonical way of avoiding this interference?.

Please, avoid answer like 2 list.

Would there be a problem to incorporate Pathfinder-2e’s “Step” action in place of DND 5e’s “Disengage” action?

Pathfinder’s Step:

You carefully move 5 feet. Unlike most types of movement, Stepping doesn’t trigger reactions, such as Attacks of Opportunity, that can be triggered by move actions or upon leaving or entering a square. You can’t Step into difficult terrain, and you can’t Step using a Speed other than your land Speed.

DND 5e’s Disengage:

If you take the Disengage action, your Movement doesn’t provoke Opportunity Attacks for the rest of the turn.

My intention would be to create for DND 5e something like:

If you take the Step action, you can move 5 feet to an unoccupied space not in difficult terrain without triggering any opportunity attacks.

As Disengage applies for a creature’s full movement, I think giving the creature an extra 5 feet of movement when taking the Step action makes up for the loss. This would of course apply for NPCs and PCs, so I don’t see this giving an unfair advantage to one group over the other, except for maybe those with the ability to disengage as a bonus action, like Goblins or Rogues; switching that for the Step action about may be a slight nerf to the class/creature/race.

I find the Pathfinder Step makes more sense than the DND Disengage, as I can’t make sense of Disengage working for more than the enemies directly threatening the character: a creature that takes the disengage action could then run there full movement, potentially avoiding a dozen or more attacks.

First time role playing, how to I address this problem?

So I am brand new the role playing as I am really shy and normally don’t like to tell my stories to other. I am role-playing with my friend and her siblings and I have a problem. I have added my character into an already existing, huge lore, place. And my friend is trying to make my character do things that would not fit my narrative. For example my character has a boyfriend and this guy is very specific to her background as they are kinda tied together by fate through different lives. Every time my OC dies, she will meet her boyfriend in the next universe, her could be her lover, friend, or enemy. My friend forced me to break up with the OC’s boyfriend and now is trying to forcefully get my OC to date a girl. I told her this character is strictly heterosexual and honestly is really mainly attracted to her boyfriend but my friend will not listen. I have other OCs who are LGBTQA+, but she is so admit on the straight one. I don’t want to cause trouble but they are constantly forcing my OC to do things out of character that I have created because she is my character. And I don’t know what to do? I don’t want to be mean or cause drama but I am stuck!

I have a problem with broken links

I have a problem with broken links and I don’t know how to fix it I will attach photos of the problem to you Links: 1- This image is from the view page source

2- This is a post-scan photo on Semrush site

The page I need help with: