PHP - Array: Calculate Square Root X - Average
Hello,
I'm trying to calculate the square root of X values in an array minus the average of the array, but the first half of the values are negative, so I'm using the abs(); function to change them to positives first, but I'm still getting "NAN" as the result for the negative values that 'should' be positive. $x = array(7,3,4,6,4,2,7); $sqrt = true; $x = sort($x); $mean = 4.71; // average $XminA = array(); foreach($x as $val) { ($sqrt == true) ? $XminA[] = round(sqrt(abs($val) - $mean),2) : $XminA[] = round($val - $mean,2); } echo "<pre>"; print_r($XminA); echo "</pre>"; and my result is... Quote [XminA] => Array ( => NAN [1] => NAN [2] => NAN [3] => NAN [4] => 1.14 [5] => 1.51 [6] => 1.51 ) Not sure what I'm doing wrong, any help is appreciated. Thank you! Kind Regards, Ace EDIT: stupid mistake, need it to the power of 2 not square root. Using the wrong function sorry: ($sqrt == true) ? $XminA[] = round(pow((abs($val) - $mean),2) : $XminA[] = round($val - $mean,2); // pow() not sqrt() Quote [XminA] => Array ( => 7.34 [1] => 2.92 [2] => 0.5 [3] => 0.5 [4] => 1.66 [5] => 5.24 [6] => 5.24 ) Similar Tutorialshi all! i have 2 tables: PRODUCTS id_prod, id_cat, date, prod_name CATEGORIES id_cat, cat_name My goal is obtain the average (day and month) of all products inserted by users in this format: category Hardwa avg daily 20, month 100 category Components: avg daily 2, month 15 and so on. PS: the 'date' field is unix timestamp (int 10). Can you help me? I'm creating a quick survey app for my son's cub scout pack's end-of-year surveys. There are two sets of questions: those where they want the responses to be completely anonymous and those questions where we need to know who filled out the response (people volunteering for positions, etc) I'm storing the responses in the db as two separate arrays, $anon and $nonAnon $anon[0] will be an array containing all the questions: $anon[0][0] = Survey question # 1 $anon[0][1] = Survey question #2, etc. The responses will be stored as arrays and placed in $anon as the 2nd element: $anon[1][0][0] = first response, answer to the first question $anon[1][0][1] = first resopnse, answer to the 2nd question $anon[1][1][0] = 2nd response, answer to the 1st question Etc. The pack leadership is concerned that no one would be able to reconstruct which anon response belonged to whom by matching up the order of the anon answers with the non-anon answers. Therefore I'd like to shuffle at least the anon responses. The long answer would be to build a temp array using the elements in $anon[1] and then shuffle that array and then reassign it to $anon[1]. Is there a way to use shuffle directly on $anon[1] without having to build a temporary array, shuffling it, then replacing the elements of $anon[1]? Hi all, How do I get the following paths from the array separately in a foreach loop? level.dat level.dat_old session.lock uid.data If I use Code: [Select] foreach($outer_dir as $key=>$val) [code] then I get a warning because its returning the folder as 'Array'. The files still upload, as well as a single file called Array. Can i just strip these from the foreach? [code] Array ( [data] => Array ( ) [level.dat] => level.dat [level.dat_old] => level.dat_old [players] => Array ( [herghost.dat] => herghost.dat ) [region] => Array ( [r.-1.0.mcr] => r.-1.0.mcr [r.0.0.mcr] => r.0.0.mcr ) [session.lock] => session.lock [uid.dat] => uid.dat ) herghost.dat Many thanks from a confused user i have problem to get the sum from the associative array. i have to get sum for the 3 result that being display from the array
rsort($sub); }
Sir, { "DiplomaFirstYear": { "2016-2017.1": 3.88, "2016-2017.2": 4, "2016-2017.3": 3.3 }, "DiplomaSecondYear": { "2016-2017.3": 4, "2017-2018.1": 3.88, "2017-2018.2": 3.94, "2017-2018.3": 3.3 }, "AdvancedDiploma": { "2017-2018.3": 4, "2018-2019.1": 3.74, "2018-2019.2": 3.62 }, "Bachelor": { "2018-2019.3": 3.15 } }
This is really strange and throwing me for a loop. I suspect there's a config setting somewhere in my PHP setup on my server which I am missing... I have a PHP script that renders a vector drawing (as a series of lines/points) into a png image. When I'm testing the script on my local machine (XAMPP + OSX) everything works great. When the script runs on my host (hostgator) the imagefilledellipse() function renders as a square instead of a circle. Screenshots below. Try the server version for yourself at http://sundrynotes.com/alpha/ (press "create new note" in the lower right then long-press on the note and select the "whiteboard" option, draw, then press "accept"). I am returning the following through JSON: Code: [Select] $this->view->lead_query=$lead_query->fetchALL(); header('OK', true, 200); header('Content-type: application/json'); echo json_encode($this->view->lead_query); I am getting the results in this format: [{"client_name":"Steve Harris","state":"TX"}] Now if the above output was displayed without the square brackets [] I can populate the values in my form correctly. Is there a way i can return the output without the square brackets? Hi all, In my string I have hidden characters that has a shape of square. When I print the string, it shows questions mark. When I opened it with notepad, it show a square shaped character. I want to remove this character in my strings. I have searched the web. Somebody says its carriage return but i think it is not. Could you please help me with this issue. Thanks alot. If you had a function that calculated the average of a fixed quantity of numbers, what type of scope issues would you anticipate? Hi. Im trying to make a PHP code that will find the average number. What I want is, a lot of input fields where you can write a number in. Then my code should take these numbers and divide them with the amount of input fields that has been written in. So that some fields you don't have to write a number, and the code will still give you a correct average. My code so far: Code: [Select] <?php if (isset($_POST['calc'])) { $m=$_POST['mat']; $e=$_POST['da']; $s=$_POST['eng']; $f=$_POST['fys']; $h=$_POST['bio']; $p=$_POST['geo']; $ave=($m+$e+$s+$f+$h+$p)/; } ?> <a href="" onclick="return hs.htmlExpand(this, { headingText: 'Beregn dit Gennemsnit:' })"> <b>Beregn dit Gennemsnit: <?php echo $ave;?></b><br></br> </a> <div class="highslide-maincontent"> <form id="gennemsnit" name="form1" method="post" action=""> Matematik<input name="math" type="text" id="mat" size="3" maxlength="4" /><br /> Dansk<input name="eng" type="text" id="da" size="3" maxlength="4" /><br /> Engelsk<input name="sci" type="text" id="eng" size="3" maxlength="4" /><br /> Fysik<input name="fil" type="text" id="fys" size="3" maxlength="4" /><br /> Biologi<input name="he" type="text" id="bio" size="3" maxlength="4" /><br /> Geografi<input name="pe" type="text" id="geo" size="3" maxlength="4" /></td><br /> <input name="calc" type="submit" id="calc" value="Beregn"/><br /><br /> </form> What I need is the code of how to divide with the amount of input fields that has been written in. thanks for any help I can't remember the math to do this, but I use MySQL to calculate an average: 5 = 100% 0 = 0% I want to make a bar that shows an average (like a bar graph) so lets say I get 2.5 as one of my returned results, that means the bar should only be 50% long of the maximum width. Using calculations, how can I get the number 50 (the max width is 100% of a table cell)? I am trying to work on a code for php where you first have a form that asks the user to input a message then input a color. When they click the submit button it takes them to the output page. It should take their message and output it into boxes in a square. And the background should turn the color that they types in. Hi, I have just created an algorithm and could this be the greatest algorithm invented for calculating square roots? Perhaps the answer is yes with 100% accuracy unlike some algorithms that round the last digit up. Below is the algorithm I have created and I used php. Also this algorithm can easily be imported into any language with any bitrate and is very scalable unlike some of the standard built in square root algorithms for some interpreters (all of the ones tested so far). Now below is the code with it in both the form of a class and the form of a function. You may notice that the function name is funny but it is tatically named that way so that the string length of the function name is the same as the sqrt() function so you don't get qwerky results when comparing the two. <?php class sqrt { public $value; function __construct($in) { $tmp = (int) $in; $tmpp = ($tmp/2); for ($i=1;($i*$i)<=$tmp;$i*=2) {} $i/=2; for (;($i*$i)<=$tmp;$i++) {} $i--; $k=$i; $i++; if (($i*$i)>$tmp || ($i*$i)<$tmp) { for ($j=1;($i*$i)>=$tmp;$j/=2,$i=($j+$k)) {} $v=strlen((string)$j); $m=1/pow(10,$v); for (;($i*$i)<=$tmp;$j+=$m,$i=($j+$k)) {} $j-=($m); $i=$j+$k; if (($i*$i)>$tmp || ($i*$i)<$tmp) { //$w = (strlen((string)pow(2,32))+1); //$w = same number as below $w = 11; //32 bit $q=$m; for ($n=$v+1;$n<$w;$n++) { $m=1/pow(10,$n); $p=pow(10,(($n-$v)+1)); for ($o=0;$o<$p && ($i*$i)<=$tmp;$j+=$m,$i=($j+$k),$o++) {} $j-=$m; $i=($j+$k); } } } echo $i; $this->value = $i; return $this->value; } } function mysq($in) { $tmp = (int) $in; $tmpp = ($tmp/2); for ($i=1;($i*$i)<=$tmp;$i*=2) {} $i/=2; for (;($i*$i)<=$tmp;$i++) {} $i--; $k=$i; $i++; if (($i*$i)>$tmp || ($i*$i)<$tmp) { for ($j=1;($i*$i)>=$tmp;$j/=2,$i=($j+$k)) {} $v=strlen((string)$j); $m=1/pow(10,$v); for (;($i*$i)<=$tmp;$j+=$m,$i=($j+$k)) {} $j-=($m); $i=$j+$k; if (($i*$i)>$tmp || ($i*$i)<$tmp) { //$w = (strlen((string)pow(2,32))+1); //$w = same number as below $w = 11; //32 bit $q=$m; for ($n=$v+1;$n<$w;$n++) { $m=1/pow(10,$n); $p=pow(10,(($n-$v)+1)); for ($o=0;$o<$p && ($i*$i)<=$tmp;$j+=$m,$i=($j+$k),$o++) {} $j-=$m; $i=($j+$k); } } } return $i; } $s = microtime(true); mysq(128); $e = microtime(true); $a=($e-$s); unset($e,$s); sleep(1); $s = microtime(true); sqrt(128); $e = microtime(true); echo 'mysq time &#160;&#160;='.$a.'<br>'; echo 'mysq result='.mysq(128).'<br>'; echo 'sqrt time&#160;&#160;='.($e-$s).'<br>'; echo 'sqrt result='.sqrt(128).'<br>'; echo 'The mysq function is '.bcdiv(substr(($e-$s),0,11),$a,0).' times faster for this calculation.<br>'; Could someone please advise the best way to determine the average of a DATE field in a SELECT query?
Nice forum here. I know nothing about PHP and need some help. Here is the deal. Members on a forum will be rating products. There will be 4 (this number could change) fields where they will select a number from a drop down menu to rate different characteristics of the product. I need to average those numbers for the overall rating. The code that outputs the individual numbers selected looks like this: {$data['record']['field_14']} 14 being one of the fields, and 15, etc. So what I need is code that takes multiple fields and outputs the average number. I appreciate any help! And please keep in mind I am not familiar with PHP coding, so if you could be as detailed as possible I would appreciate it. Thanks! Hi,
I have a blog which records the amount of views on each article. I now want to be able to work out the average number of views per hour.
How can I work out the number of hours passed from a datetime format?
From there I can just do views divided by hours passed.
Thanks in advance!
Hi, Firstly, these are my tables: CLASS class_id class_name 1 Donkeys 2 Monkeys 4 Classic 9 Humans COURSES class_id courses_number 9 6 9 2 1 3 2 2 I would like to print average course_number for each class_name. So for class_name Donkeys would have average course_number 3. And for clasS_name Humans, average course_number is 4. Do you get my point? Hi, I'm trying to get out the average of records stored in a mysql table This is the code im using right now Code: [Select] mysql_query("SELECT DATE(dato) , COUNT( dato ) AS counted FROM dekodere GROUP BY date(dato)", $link); $ave = mysql_num_rows($ave); This is getting out the average, but i need to exclude weekends because there is not stored anything during the weekend so it's making the average go off.. any tips? I manage to display data using below query that will show value for each month. How to calculate average value starting july onwards(based on user selection).
Let say the value for element 'A' are Jul=80, Aug= 80, Sep=90. If user select Aug then the average is 80 and if user select Sep then the average is 83.
Query:
$sql2 = "Select element, SUM(CASE WHEN Month = 'Jan' THEN total ELSE 0 END ) AS Jan, SUM(CASE WHEN Month = 'Feb' THEN total ELSE 0 END ) AS Feb, SUM(CASE WHEN Month = 'Mac' THEN total ELSE 0 END ) AS Mac, SUM(CASE WHEN Month = 'Apr' THEN total ELSE 0 END ) AS Apr, SUM(CASE WHEN Month = 'May' THEN total ELSE 0 END ) AS May, SUM(CASE WHEN Month = 'Jun' THEN total ELSE 0 END ) AS Jun, SUM(CASE WHEN Month = 'Jul' THEN total ELSE 0 END ) AS Jul, SUM(CASE WHEN Month = 'Aug' THEN total ELSE 0 END ) AS Aug, SUM(CASE WHEN Month = 'Sep' THEN total ELSE 0 END ) AS Sep, SUM(CASE WHEN Month = 'Oct' THEN total ELSE 0 END ) AS Oct, SUM(CASE WHEN Month = 'Nov' THEN total ELSE 0 END ) AS Nov, SUM(CASE WHEN Month = 'Dec' THEN total ELSE 0 END ) AS Dis FROM tbl_ma GROUP BY element"; $rs2 = mysql_query($sql2); $getRec2 = mysql_fetch_assoc($rs2);Below is how print the data: <?php while ($row = mysql_fetch_assoc($rs2)) { ?> <tr> <td style="color:black;background-color:#f5efef"><div align="left"><?php echo $row['element']; ?></div></td> <?php if( $year != '2014' ){ ?> <?php if( 1 <= $monthID ): ?><td><div align="center" style="color:black"><?php echo $row['Jan']; ?></div></td><?php endif; ?> <?php if( 2 <= $monthID ): ?><td><div align="center" style="color:black"><?php echo $row['Feb']; ?></div></td><?php endif; ?> <?php if( 3 <= $monthID ): ?><td><div align="center" style="color:black"><?php echo $row['Mac']; ?></div></td><?php endif; ?> <?php if( 4 <= $monthID ): ?><td><div align="center" style="color:black"><?php echo $row['Apr']; ?></div></td><?php endif; ?> <?php if( 5 <= $monthID ): ?><td><div align="center" style="color:black"><?php echo $row['May']; ?></div></td><?php endif; ?> <?php if( 6 <= $monthID ): ?><td><div align="center" style="color:black"><?php echo $row['Jun']; ?></div></td><?php endif; ?> <?php } ?> <?php if( 7 <= $monthID ): ?><td><div align="center" style="color:black"><?php echo $row['Jul']; ?></div></td><?php endif; ?> <?php if( 8 <= $monthID ): ?><td><div align="center" style="color:black"><?php echo $row['Aug']; ?></div></td><?php endif; ?> <?php if( 9 <= $monthID ): ?><td><div align="center" style="color:black"><?php echo $row['Sep']; ?></div></td><?php endif; ?> <?php if( 10 <= $monthID ): ?><td><div align="center" style="color:black"><?php echo $row['Oct']; ?></div></td><?php endif; ?> <?php if( 11 <= $monthID ): ?><td><div align="center" style="color:black"><?php echo $row['Nov']; ?></div></td><?php endif; ?> <?php if( 12 <= $monthID ): ?><td><div align="center" style="color:black"><?php echo $row['Dis']; ?></div></td><?php endif; ?> <td><div align="center" style="color:black"><?php //echo average; ?></div></td> </tr> <?php } ?> I have a "Users" table. I would like to find out the average users sign up in total. This table has a "joined date" column so I can track how many users sign up in a single day. For e.g. August 16 - 10 users August 17 - 20 users Auguest 18 - 30 users The total average of user sign ups would be 20 users based on the above results. So I am wondering how can I create this function? This is my starting query. $get_users = $db->prepare("SELECT user_id FROM users"); $get_users->execute(); $result_users = $get_users->fetchAll(PDO::FETCH_ASSOC); if(count($result_users) > 0) { foreach($result_users as $row) { $user_id = $row['user_id']; } }
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