warning messages – Some of the functions have zero differential order

I am trying to solve the following system of differential equations, but Mathematica (11.3) complains that

NDSolveValue::pdord Some of the functions have zero differential order

I do not understand this message since all of the functions appear with their derivatives in the equations.

Here is the code:

(Rho)0 = 1;
M = 1;
eq1 = D(m(t, r), r) - 4 Pi (Rho)(t, r) R(t, r)^2 D(R(t, r), r);
eq2 = D(m(t, r), t) + (4 Pi)/3 (Rho)(t, r) R(t, r)^2 D(R(t, r), t);
eq3 = D(R(t, r), r, t) - D(R(t, r), t) D((Nu)(t, r), r) - 
   D(R(t, r), r) D((Lambda)(t, r), t);
eq4 = D((Rho)(t, r), r) + 1/4 (Rho)(t, r) D((Nu)(t, r), r);
eq5 = Exp(-2 (Nu)(t, r)) (D(R(t, r), {t, 2}) - 
      D((Nu)(t, r), t) D(R(t, r), t)) - 
   Exp(-2 (Lambda)(t, r)) D((Nu)(t, r), r) D(R(t, r), r) + m(t, r)/
   R(t, r)^2 + (4 Pi)/3 (Rho)(t, r) R(t, r);
{Ro, Ra, Ma, nu, la} = 
 NDSolveValue({eq1 == 0, eq2 == 0, eq3 == 0, eq4 == 0, 
   eq5 == 0, (Rho)(0, r) == (Rho)0, (Rho)(t, 0) == (Rho)0, 
   m(0, r) == M, 
   m(t, 0) == 
    M, (Nu)(0, r) == -(1/4) Log((Rho)0), (Nu)(t, 
     0) == -(1/4) Log((Rho)0), (Lambda)(0, r) == 
    0, (Lambda)(t, 0) == 0, R(0, r) == ((3 M)/(4 Pi (Rho)0))^(1/3), 
   R(t, 0) == ((3 M)/(4 Pi (Rho)0))^(1/3), 
   Derivative(1, 0)(R)(0, r) == 1}, {(Rho), R, 
   m, (Nu), (Lambda)}, {t, 0, 1}, {r, 0, 1})

Note: another message appears saying that the initial and boundary conditions are inconsistent, but that is another problem I have to solve later, I am more concerned with the other message at the moment.

tweening – Godot tween animation playing order

I’m making a three in line game with godot, but i’m having an issue.

First time when swapping cells, the animation of swapping and the elimination of cells (in the case of making 3 or more cell aligned in a line) played both at the same time.

So i refactored a bit the code, now i have queue for each cell that manages the animation to be played one by one.

Now my problem is this, the cells that the player swaps, they do fine, the play the swap animation then the elimination animation. the problem are the other cells in the line, those get removed as the first cells are playing the swap animation first and then elimination animation.

| *              | Step 1           | Step 2          |  
| cells in line  |  remove animation|   nothing       |
| swaped cells   |  swap animation  | remove animation|

in case i didn’t explained well i left a more graphic description of the flow of the animation steps.

this is how i want the animation to be played

| *              | Step 1           | Step 2            |  
| cells in line  |  nothing         |   remove animation|
| swaped cells   |  swap animation  | remove animation  |

I’m not sure how to solve the problem, each cell manages their animations in the queue.

google apps script – How to combine multiple ranges with getRange in order to clear the contents of specific cells?


I use this sheet to enter data of patients in (Data_Entry) tab. Specific rows are titles and should not be cleared whenever I clear contents of all cells in the sheet/tab. Like Rows 1-4 and rows 20-21. So I made this script to clear specific cells but it seems very basic and it has a problem whenever somebody inserts a new row in between, the whole range needs to be adjusted.

The script has three functions: adding_menu, making borders of query results in (All_patients)tab and ClearContents of (Data_Entry) tab.

So my question is about the last function (ClearContent)

 function onOpen() {

    var menuItems = (
    {name: 'ClearContents', functionName: 'ClearContents'},
    {name: 'Borders', functionName: 'borders'}
  SpreadsheetApp.getActiveSpreadsheet().addMenu('Weekened_Functions', menuItems);

function borders() {
  var range = SpreadsheetApp.getActive().getSheetByName('All_Patients').getDataRange();
  var cell = SpreadsheetApp.getActive().getSheetByName('All_Patients').getRange("B50:H200")
  cell.setBorder(false, false, false, false, false, false);
  var values = range.getValues();
  for (var i = 2; i < values.length; i++) {
    for (var j = 1; j < values(i).length; j++) {
        range.getCell(i + 1, j + 1).setBorder(true, true, true, true, true, true);
function ClearContents() {
  var sheet = SpreadsheetApp.getActive().getSheetByName('Data_Entry');



1 how to combine these ranges in simple formula?

2 Is there a way to add exception like: (clear contents of all cells except Column M and Column A and cells containing text “Ward” or “room”or problem list” or “recommendations”?

how to group export order by product in file csv in magento 2.3

j’ai une command export:order qui permet d’exporter les commandes dans un fichier csv et il y a un problème d’exportation de donnée en groupe par produit
enter image description here

plugin development – Woocommerce add custom metabox to order with query variable

I’m little frustrated with a problem.

Externally i load to my website a custom query variable on the URL.
Example: https://mywebsite.com/mypage/?source=webview?origin=Android

Varibles: source=webview and origin=Android or origin=IOS

This variables let me know if the web is loaded from my webview app and what OS has the device (IOS or Android).

I try a lots of ways to get this work.
One of this ways is trying to use $_GET like this example:

 add_action('woocommerce_checkout_create_order', 'before_checkout_create_order3', 20, 2);
    function before_checkout_create_order3( $order, $data ) {
        $origen3 = $_GET('device');
        $order->update_meta_data( '_origen3', $origen3 );


But i can’t save with php the Device and always have an empty value on my var.

Y also try with get_query_var and here i have two problems.
When i try to save the variable with get_query_var like this:

$device = get_query_var( 'Device' );

I have an empty variable.

If i declare the query_var i have a redirection error.
This is my example:

        function test_query_vars( $qvars ) {
    $qvars() = 'device';
    return $qvars;
add_filter( 'query_vars', 'test_query_vars' );

Here i think is something missing because i get the device saved but when i try to go to the home the page redirect to another page. I try re-save the permalinks and the .htaccess file but nothing works.

tnks on advice.

Mandatory Fields Error on Manual order pay page – woocommerce

I’m facing issues with required mandatory fields on the manually generated orders page (payment link through email).

WooCommerce scenario: an order is created by admin. This order’s payment link is sent by email to the customer to pay.

Link like this:


The problem is that when I’m trying to proceed with the payment it says

"Sorry, there was an error: The field Address is mandatory., The field City Name is mandatory."

My question is, there are no user entry fields on this page then why it is showing mandatory fields required. FYI this is working fine on chrome browsers(desktop only) but when the same link is accessed from chrome mobile or safari the error shows up. above give link is the working link, kindly assist me here.

I’m not using any kind of plugin to manage checkout fields.
This feels strange as there are no fields on the page but it still shows the required fields error.

class diagram – UML , what is the correct order of steps?

Bart van Ingen Schenau’s answer is right in that UML is just a language and not a methodology. However, there are some methodologies that are built around tools (including UML), such as the Rational Unified Process. Different UML diagrams are used throughout the different phases of RUP.

It’s not really possible to specifically say how you can fit graphical modeling into your process without an understanding of your process. A sequential process is going to look different than an iterative and incremental process, for example. If you’re basing your methodology on the agile and lean principles, that will also guide how you can apply graphical modeling into your process.

In a sequential process, Activity, State, and Use Case diagrams will likely be the first created. These can be used to capture business processes and activities at a much higher level of abstraction than some of the other diagrams. You may also start to see abstract Class, Component, and Sequence diagrams to start to capture business relations, but these will evolve over time to be more detailed. The other diagrams are closer to the architecture and code and will be created as you define your architecture.

The exact diagrams that you create will depend on what you are trying to communicate and who you are trying to communicate with. There’s not much value in creating diagrams that don’t help someone understand the system under design or progress with work. There are also diagrams and modeling techniques that aren’t part of UML that could be useful.

Compilation from source: LESS file is empty: order email sent without css and an warning

Getting this error while sending order emails.Compilation from source: LESS file is empty: order email sent without css and an warning

What is boot order of different user-mode persistence mechanisms in Windows?

There are many persistence mechanisms in windows :

Boot drivers, CurrentVersionRun key, task scheduler startup, startup services, and so on..

So obviously Boot drivers are the fastest, But I’m talking about user-mode mechanisms, so what are the earliest user-mode persistence mechanism in windows?

I want to know the general order, for example does the boot services start first, then currentversionrun key, or..? what about task scheduler startup? and so on..

Display customer_note in order confirmation email

I am using this code to display customer_note in order confirmation email:

{{var order.getCustomerNote()|escape|nl2br}}

But it does not show up in the email. I also checked the value of customer_note in sales_order table to make sure it’s not null.
And i went to Order model:


And return a test string:

 * Return customer_note
 * @return string|null
public function getCustomerNote()
    return "i was here!";
    return $this->getData(OrderInterface::CUSTOMER_NOTE);

Surprisingly i can see my test string show up in email.

Do you have any ideas why it doesnt work?
Many thanks.