I am trying to simulate a simple circuit using a simulation program like SPICE. In the beginning of the circuit I have a pulse train voltage source, later it is connected to a normal LPF. The voltage source frequency is set as 1 kHz, my question is how to increase this frequency? 

The only options that I have is to change the time of the cycle and the voltage. If I set 1 ms and 5V, the frequency will be 1 kHz.

If I change the time to 0.5 ms, the result will be 5V for 0.5 ms and the rest is 0. (The second cycle will not start after 0.5 ms, so the frequency is same 1 kHz). Strange!

How do I increase the frequency of the voltage source?


Question: Show comments fields in two columns
Answer: What you need are two new containers: one for the single line fields, one for the textarea. Looking at the default comment form, we can see where their start and end tags should appear. I have added some comments to make that easier to see:

&lt;form action="&lt;?php echo site_url( '/wp-comments-post.php' ); ?&gt;" method="post" id="&lt;?php echo esc_attr( $args['id_form'] ); ?&gt;"&gt;
    &lt;?php do_action( 'comment_form_top' ); ?&gt;
    &lt;?php if ( is_user_logged_in() ) : ?&gt;
        &lt;?php echo apply_filters( 'comment_form_logged_in', $args['logged_in_as'], $commenter, $user_identity ); ?&gt;
        &lt;?php do_action( 'comment_form_logged_in_after', $commenter, $user_identity ); ?&gt;
    &lt;?php else : ?&gt;
        &lt;?php echo $args['comment_notes_before']; ?&gt;
        &lt;?php
        do_action( 'comment_form_before_fields' );
        // Fields: author, email, url
        foreach ( (array) $args['fields'] as $name =&gt; $field ) {
            echo apply_filters( "comment_form_field_{$name}", $field ) . "\n";
        }
        do_action( 'comment_form_after_fields' );
        ?&gt;
    &lt;?php endif; ?&gt;
    &lt;?php 
    // Field: textarea
    echo apply_filters( 'comment_form_field_comment', $args['comment_field'] ); ?&gt;
    &lt;?php echo $args['comment_notes_after']; ?&gt;
    &lt;p class="form-submit"&gt;
        &lt;input name="submit" type="submit" id="&lt;?php echo esc_attr( $args['id_submit'] ); ?&gt;" value="&lt;?php echo esc_attr( $args['label_submit'] ); ?&gt;" /&gt;
        &lt;?php comment_id_fields( $post_id ); ?&gt;
    &lt;/p&gt;
    &lt;?php do_action( 'comment_form', $post_id ); ?&gt;
&lt;/form&gt;



We need the first start tag on 'comment_form_top'. Not later because we have to catch the case of a user who is logged in.
We close that tag and open the second one on 'comment_form_after_fields'.
Finally, we close the last tag after 'comment_form_field_comment'. This one is a filter, not an action.


In the following sample code I throw a style element into the markup. In your theme you should put the CSS into the style sheet. And you should use a clearfix handler of your choice, not the markup I used here. :)

add_action( 'comment_form_top', 'wpse_67805_open_tag' );
function wpse_67805_open_tag()
{
    ?&gt;
&lt;style&gt;
@media screen and (min-width: 800px) {
    .wpse-67805-comment-fields,
    .logged-in-as {
        float: left;
        width: 280px;
    }
    .wpse-67805-comment-textarea {
        float: right;
        width: 280px;
    }
    .wpse-67805-textarea-after {
        clear: both;
    }
}
&lt;/style&gt;
&lt;div class="wpse-67805-comment-fields"&gt;
    &lt;?php
    }
    add_action( 'comment_form_after_fields', 'wpse_67805_open_close_tag' );
    add_action( 'comment_form_logged_in_after', 'wpse_67805_open_close_tag' );
    function wpse_67805_open_close_tag()
    {
        ?&gt;&lt;/div&gt;&lt;div class="wpse-67805-comment-textarea"&gt;&lt;?php
    }
    add_filter( 'comment_form_field_comment', 'wpse_67805_close_tag' );
    function wpse_67805_close_tag( $textarea )
    {
        return "$textarea&lt;/div&gt;&lt;div class='wpse-67805-textarea-after'&gt;&lt;/div&gt;";
    }


Result in TwentyEleven



Not exactly beautiful, you have to adjust the CSS. But the general way should be clear now.