I'm trying to get percentage of two numbers in my app (laravel based) but i don't get the right numbers.
Code:
$pdts->price = 123.234
$pdts->newprice = 90.500
{{number_format($pdts->newprice / $pdts->price * 100, 0) } }%
it returns -73%, it should return -27%. How do I correct this?
Update To those still didn't get it
Guys I did defined my goal / what i'm looking for it should return -27%. How do I correct this? so I was looking to get -27% as the result and thanks to commenters I did find my solution.
I don't understand all this vote-downs and continued comments.
This is not really a programming question, it's more a math question.
But to get the result you want you need to calculate the difference in percentage.
//(123.234-90.500)/123.234*100
- {{number_format(($pdts->price - $pdts->newprice) / $pdts->price * 100, 0) } }%
// -27%
Try this one,
$value = ($pdts->price-$pdts->newprice) / $pdts->price * 100;
$percentage = (int)($value).'%';
Here, percentage variable will have your required value.
Related
I have a code that looks for the smallest number in the average column. When in mysql, I put the column in "double", it works. But for some reasons and particular actions, my column must be in "text". I need a php / SQL code to show the smallest number.otherwise my code tells me that 13.06 is smaller than 8.56.here is my code:
$sql1 = "SELECT MIN(moyenne)as moyenneP FROM rangec where classe = '".$_SESSION['classroom']."' AND position = '".$_SESSION['anscol']."'
AND ecoles= '".$_SESSION['ecoles']."' AND trimestre= '".$_SESSION['trimestre']."'";
foreach ($bdd->query($sql1) as $classement)
{
$moyenneP =$classement['moyenneP'];
$moyenneP=''.round($moyenneP, 2).'';
}
I believe I have been explicit! Thank you in advance for your assistance.
I want to check a point exists in a polygon or not using GEOPHP in Drupal. I have created the polygon and got the coordinates from http://www.birdtheme.org/useful/v3tool.html.
$userLocation = geoPHP::load("POINT(77.600555 12.965416)","wkt");
$storeServingArea=geoPHP::load("POLYGON((77.569656 12.986159, 77.596779 12.993518, 77.622185 12.973780, 77.623215 12.954710, 77.608109 12.945676, 77.577896 12.945341, 77.565880 12.957386, 77.565193 12.976122, 77.568970 12.985824))","wkt");
var_dump($storeServingArea->contains($userLocation));
This code gives the result as NULL.
Then I tried to exchange the values of latitude and longitude and tested like this:
$userLocation = geoPHP::load("POINT(12.965416 77.600555)","wkt");
$storeServingArea=geoPHP::load("POLYGON((12.986159 77.569656, 12.993518 77.596779, 12.973780 77.622185, 12.954710 77.623215, 12.945676 77.608109, 12.945341 77.577896, 12.957386 77.565880, 12.976122 77.565193, 12.985824 77.568970))","wkt");
var_dump($storeServingArea->contains($userLocation));
This also give the result as NULL.
What could be the possible mistake I'm doing here? how can I fix it?
SOLUTION:
Helpful link: Check if Google Map Point is in polygon from PHP
I fixed my issue with the following link:
http://assemblysys.com/php-point-in-polygon-algorithm/
I have forked geoPHP and added Polygon->pointInPolygon and MultiPolygon->pointInPolygon methods for that purpose. Take a look: https://github.com/sookoll/geoPHP
$point = \geoPHP::load('POINT (x y)','wkt');
$polygon = \geoPHP::load('POLYGON ((x y...))','wkt');
$point_is_in_polygon = $polygon->pointInPolygon($point);
I need to go through an array containing points in a map and check their distance from one another. I need to count how many nodes are within 200m and 50m of each one. It works fine for smaller amounts of values. However when I tried to run more values through it (around 4000 for scalability testing) an error occurs saying that I have reached the maximum execution time of 300 seconds. It needs to be able to handle at least this much within 300 seconds if possible.
I have read around and found out that there is a way to disable/change this limit, but I would like to know if there is a simpler way of executing the following code so that the time it takes to run it will decrease.
for($i=0;$i<=count($data)-1;$i++)
{
$amount200a=0;
$amount200p=0;
$amount50a=0;
$amount50p=0;
$distance;
for($_i=0;$_i<=count($data)-1;$_i++)
{
$distance=0;
if($data[$i][0]===$data[$_i][0])
{
}
else
{
//echo "Comparing ".$data[$i][0]." and ".$data[$_i][0]." ";
$lat_a = $data[$i][1] * PI()/180;
$lat_b = $data[$_i][1] * PI()/180;
$long_a = $data[$i][2] * PI()/180;
$long_b = $data[$_i][2] * PI()/180;
$distance =
acos(
sin($lat_a ) * sin($lat_b) +
cos($lat_a) * cos($lat_b) * cos($long_b - $long_a)
) * 6371;
$distance*=1000;
if ($distance<=50)
{
$amount50a++;
$amount200a++;
}
else if ($distance<=200)
{
$amount200a++;
}
}
}
$amount200p=100*number_format($amount200a/count($data),2,'.','');
$amount50p=100*number_format($amount50a/count($data),2,'.','');
/*
$dist[$i][0]=$data[$i][0];
$dist[$i][1]=$amount200a;
$dist[$i][2]=$amount200p;
$dist[$i][3]=$amount50a;
$dist[$i][4]=$amount50p;
//*/
$dist.=$data[$i][0]."&&".$amount200a."&&".$amount200p."&&".$amount50a."&&".$amount50p."%%";
}
Index 0 contains the unique ID of each node, 1 contains the latitude of each node and
index 2 contains the longitude of each node.
The error occurs at the second for loop inside the first loop. This loop is the one comparing the selected map node to other nodes. I am also using the Haversine Formula.
first of all, you are performing in big O notation: O(data^2), which is gonna be slow as hell , and really, either there are 2 possible solutions. Find a proven algorithm that solves the same problem in a better time. Or if you cant, start moving stuff out of the innner for loop, and mathmatically prove if you can convert the inner for loop to mostly simple calculations, which is often something you can do.
after some rewriting, I see some possiblities:
If $data is not a SPLFixedArray (which has a FAR Better access time, ) then make it. since you are accessing that data so many times (4000^2)*2.
secound, write cleaner code. although the optizmier will do its best, if you dont try either to minize the code (which only makes it more readable), then it might not be able to do it as well as possible.
and move intermediate results out of the loops, also something like the size of the array.
Currently you're checking all points against all other points, where in fact you only need to check the current point against all remaining points. The distance from A to B is the same as the distance from B to A, so why calculate it twice?
I would probably make an adjacent array that counts how many nodes are within range of each other, and increment pairs of entries in that array after I've calculated that two nodes are within range of each other.
You should probably come up with a very fast approximation of the distance that can be used to disregard as many nodes as possible before calculating the real distance (which is never going to be super fast).
Generally speaking, beyond algorithmic optimisations, the basic rules of optimisation are:
Don't any processing that you don't have to do: Like not multiplying $distance by 1000. Just change the values you're testing against from 20 and 50 to 0.02 and 0.05, respectively.
Don't call any function more often than you have to: You only need to call count($data) once before any processing starts.
Don't calculate constant values more than once: PI()/180, for example.
Move all possible processing outside of loops. I.e. precalculate as much as possible.
Another minor point which will make your code a little easier to read:
for( $i = 0; $i <= count( $data ) - 1; $i++ ) is the same as:
for( $i = 0; $i < count( $data ); $i++ )
Try this:
$max = count($data);
$CONST_PI = PI() / 180;
for($i=0;$i<$max;$i++)
{
$amount200a=0;
$amount50a=0;
$long_a = $data[$i][2] * $CONST_PI;
$lat_a = $data[$i][1] * $CONST_PI;
for($_i=0;$_i<=$max;$_i++)
//or use for($_i=($i+1);$_i<=$max;$_i++) if you did not need to calculate already calculated in other direction
{
$distance=0;
if($data[$i][0]===$data[$_i][0]) continue;
$lat_b = $data[$_i][1] * $CONST_PI;
$long_b = $data[$_i][2] * $CONST_PI;
$distance =
acos(
sin($lat_a ) * sin($lat_b) +
cos($lat_a) * cos($lat_b) * cos($long_b - $long_a)
) * 6371;
if ($distance<=0.2)
{
$amount200a++;
if ($distance<=0.05)
{
$amount50a++;
}
}
} // for %_i
$amount200p=100*number_format($amount200a/$max,2,'.','');
$amount50p=100*number_format($amount50a/$max,2,'.','');
$dist.=$data[$i][0]."&&".$amount200a."&&".$amount200p."&&".$amount50a."&&".$amount50p."%%";
} // for $i
It will be better to read I think and if you change the commented out line of the for $_i it will be faster at all :)
I am trying to find a php equivalent of processing's "map" function so I can re-map a number from one range to another. Does anything exist? Is it called something different?
http://processing.org/reference/map_.html
For example to map a value from 0-100 to 0-9.
map(75, 0, 100, 0, 9);
There is no native function for doing this, but it's easy to create:
function map($value, $low1, $high1, $low2, $high2) {
return ($value / ($high1 - $low1)) * ($high2 - $low2) + $low2;
}
This is untested, but you should hopefully get the idea.
Thanks for this great function!
I would personally improve a bit this function by adding simple error checking, to avoid dividing by 0, which would make PHP have a fatal error.
function map($value, $low1, $high1, $low2, $high2) {
if ($low1 == $high1)
return $low1;
return ($value / ($high1 - $low1)) * ($high2 - $low2) + $low2;
}
I have a rectangular map, stored as multidimensional array (ie $map[row][col]) and I have to track down which squares are seen by a player, placed anywhere on this map.
Player visibility is circular with unknown radius (but given at run-time) and I only need integer solutions.
I know that circumference formula is
x^2 + y^2 <= r^2
but how can I store everything?
I need these values since then I can "reveal" map squares.
The best would be a multidimesional array (ie __$sol[x][y]__).
This is a piece of code that I'm using. It's not corrected since it assumes that vision is a square and not a circle.
Calculating the square
$this->vision_offsets_2 = array();
//visibility given as r^2
$mx = (int)(sqrt($this->viewradius2));
$mxArr = range($mx * -1, $mx + 1);
foreach ($mxArr as $d_row)
{
foreach ($mxArr as $d_col)
{
$this->vision_offsets_2[] = array($d_row, $d_col);
}
}
This is how I apply that
foreach($player as $bot)
{
foreach($visibility as $offset)
{
$vision_row = $offset[0] + $bot[0];
$vision_col = $offset[1] + $bot[1];
if(isset($map[$vision_row][$vision_col]))
{
if( $map[$vision_row][$vision_col] == UNSEEN) {
$map[$vision_row][$vision_col] = LAND; }
}
}
}
Here you can find the bot view: as you can see is a non perfect circle.
How can I track it? By the way, in this example radius^2 is 55, the orange circle is the player, brown squares are visible ones.
Structure
You're already referencing terrain in a grid. Store terrain objects in those grid values. Apply attributes to those objects. Check with something like
$map[$x][$y]->isVisible($player);
You'll need some methods in there for setting vision and tests for checking the user that is passed against a list of users who can see it. While you're at it, setup other related methods in those objects (I see references to land... isLand() and isWater() perhaps?).
You can even have vision cascade within objects such that you only need to move the position of a user and the object takes care of triggering off all the code to set nearby plots of land to visible.
Math
We are given circumference.
double diameter = circumference / 3.14159
double radius = diameter / 2 //Normally done in one step / variable
Now we must know the distance between two points to compare it. Let's use map[4][7] and map[3][9].
int x0 = 4;
int y0 = 7;
int x1 = 3;
int y1 = 9;
double distance = Math.sqrt(
Math.pow(x0 - x1, 2) +
Math.pow(y0 - y1, 2)
);
System.out.println(distance); //2.23606797749979
Test distance > radius.
Testing each square
Put the above in a method: visibleFrom(Square target)
radius should be a globally accessible static variable when comparing.
Your Square object should be able to hand over its coordinates.
target.getX()
target.getY()
Some optimizations can be had
Only checking things for circular distance when they're in the square.
Not checking anything for circular distance when purely along the x or y axis.
Figuring out the largest square that fits inside the circle and not checking boxes in that range for circular distance.
Remember that premature optimization and over optimization are pitfalls.
A function like this would tell you if a map square is visible (using the distance of the centers of the squares as a metric; if you want to define visibility in another manner, which you probably would, things get much more complicated):
function is_visible($mapX, $mapX, $playerX, $playerY, $r) {
return sqrt(pow($mapX - $playerX, 2) + pow($mapY - $playerY, 2)) <= $r;
}
You probably don't really need to store these values since you can easily calculate them on demand.
I think that Bresenham's circle drawing algorithm is what you're looking for.
I don't know exactly what you want, but here's some things that should help you along. As a warning these are untested, but the logic is sound.
//You mentioned circumference, this will find out the circumference but I don't
//think you actually need it.
$circumference_length = 2 * $visibility_range * 3.1415;
//Plug in the player and target coordinates and how far you can see, this will
//tell you if the player can see it. This can be optimized using your object
//and player Objects.
function canSee($player_x, $player_y, $vision_length, $target_x, $target_y){
$difference_x = $target_x - $player_x;
$difference_y = $target_y - $player_y;
$distance = sqrt((pow($difference_x,2) + pow($difference_y, 2));
if($vision < $distance){
return false;
} else {
return true;
}
}
Edit: In response to your clarification, you can use the above function to figure out if you should show the terrain objects or not.
foreach($player as $bot)
{
foreach($terrain_thing as $terrain)
{
//ASSUMING THAT [0] IS ALWAYS X AND [1] IS ALWAYS y, set a third variable
//to indicate visibility
$terrain["is_visible"] = canSee($bot[0], $bot[1], $visibility_range, $terrain[0], $terrain[1])
}
}