Author: Akshay Upadhyay

When do you need to add Custom CRS projection to add in QGIS? After all QGIS supports more than 2700 predefined CRS – Coordinates Reference system. Which is very common and is also installed in PostGIS database. But there are times when you receive a GIS data files in different CRS or projections or when somebody or your clients wants the GIS data files in a different CRS. At this time you may enquire to look into Custom CRS.

I got the same case, when one of my client was trying to convert a GML file to KML file. It would be a different topic to understand or find the CRS of GIS file. When my client asked for the problem they were facing while using the tool, I had jumped over to find the issue to solve it. As the file the user was trying to convert was GML file, which can also be opened in Text editor, I was able to easily figure out the projection the file is in. Which I found is very rarely used and it was not supported by the tool then. Finally we had converted the file from backend and was able to successfully resolve the clients problem.

Let me give you step by step procedure to make a file supports custom CRS and render it accordingly in QGIS.

Steps to Add Custom CRS projection in QGIS

1.) Open up QGIS. On the top Navbar of QGIS, select Settings option and click on Custom CRS or Custom Projection option. (In both version of QGIS 2.x or QGIS 3.x you will be getting this options for Custom CRS projection). This will open up a new Window in QGIS with different options.

2.) In the window, click on + or plus sign and give a name to the CRS. And under parameter option, put the values in proj4 definition of CRS.

Most of the time, you will be able to get the projection value in WKT format and not in proj4 format. While to add custom CRS QGIS supports proj4 format to be added.

For example here, in my case, I was know that the GML file is having the PCS_Lambert_Conformal_Conic projection. And for the same to support in QGIS, I wanted get to the proj4 value of PCS_Lambert_Conformal_Conic. So I was able to find out the link to get the wkt of PCS_Lambert_Conformal_Conic. Somehow I was not able to get the proj4 which this website support.

So I converted wkt to proj4 format of CRS with gdalsrsinfo open source tool of GDAL.

gdalsrsinfo -o proj4 example.prj

Once done save the changes. QGIS also provides a testing tool, where we can provide the WGS 84 coordinates and get the coordinates of newly added custom CRS projection.

3.) Now after adding the custom projection or custom CRS, you can find the option to change the CRS of the layer or file added. That is, right click on layer and click on Set layer CRS. Search and Select the custom CRS or projection Added.

This would make your file to work properly, as how you want it.Hope this tutorial helps you to Add Custom CRS or Custom Projection in QGIS, and render or display the file properly. If you found any issue while performing the steps please comment below.

IGISMAP Analysis is the Number 1 Alternative of Carto Platform. Carto is one of the GIS Cloud Software as a Service platform, which provides many functionality, but you will get many other reasons for which you might be looking for the alternative of Carto. Either looking for effective pricing and team management without enterprise plan, IGISMAP has many benefits over Carto.com. In General both tends to achieve the same purpose, i.e Either creating and sharing or embedding maps without writing any code or getting it achieved through the use of APIs. But there are few points which you might look into IGISMAP as a preference over carto. Check Alternative of ArcGIS online.

Ultimate Carto Alternative – IGISMAP Analysis

Lets found out all the best possibility reason which stands why IGISMAP can be better choice for you in comparision to Carto Database.

Cost Effective – IGISMAP is 10 times cheaper than Carto:

Yes you read it right. Where carto cost you $299 for a month subscription for 500 MB of data, IGISMAP Analysis cost you just $30 per month for the same 500MB of data. Similarly if you look for annual subscription, carto will cost you $2388 while IGISMAP analysis will cost you just $300 i.e you will save $2088. Making sure that IGISMAP Analysis tool have all features covers which all major GIS cloud as well as desktop application covers.

What else? IGISMAP Analysis provides multiple users add supports i.e adding Administrators, Developers and Business user to access map, which Carto Individual plan misses. Effective Price with more features covered is what IGISMAP USP is.

IGISMAP Supports Raster data as well Vector data upload:

IGISMAP Supports Raster (GeoTiff – Raster geo-referenced image) along with Vector files where carto does not provides the raster files. This makes stand out of Carto. While both tool are capable to supports all kinds of vector data like CSV, Excel, ESRI Shapefile, KMZ, KML, GeoJSON (TopoJOSN which only IGISMAP Supports), MapInfo, GPX and many more.

Digitise map by creating point, line and polygon layer – only available feature in IGISMAP Analysis:

IGISMAP Analysis Supports to add and create point, line and polygon layer separately and digitised the data. Unlike Carto and other online mapping system tool. Generally you will get this functionality in GIS desktop application like QGIS, ArcGIS etc. Here at IGISMAP Analysis you will also be able to add the data to existing layer, edit the attribute and delete the layers. You can also create a survey system with the layers you provide so that the your developers can add more data on your layer and can contribute easily.

IGISMAP Analysis provides More Data storage compare to sample plan of Carto:

IGISMAP analysis provides 30 times more storage as compare to Carto plan. I.E where carto for $299 per month provides only upto 512 MB of storage, IGISMAP provides 10 GB of data for just $200 plan. Along with such a huge difference in pricing and storage, IGISMAP also makes sure security at its high priority for customer data to access. IGISMAP Analysis Cloud system is hosted on AWS servers with the premium infrastructure used and With 100% uptime and availability of server.

Dedicate Support in IGISMAP while Basic Support in Carto:

IGISMAP support is responsive and make sure to solve each and every query of the customer. Along with that, we at IGISMAP also supports and helps to create Maps for you. A dedicated customer support manager is assigned to every one of the customer and customer will be able to communicate easily if they face any issue. We can be contacted by email or our personalised chat box 24/7. While Carto support basic customer support at specific timing. For a dedicated support you need to be Carto Enterprise customer.

Comparison table between IGISMAP and Carto plans: Alternative of Carto – IGISMAP Analysis Tool

This table will provide only key difference between IGISMAP and Carto which we feel should be highlighted. Rest other major features are supported by both the platform.

IGISMAP Analysis stands as best alternative of Carto – Here are more points to cover:

• No coding skills required – Just drag and Drop and Few clicks to create Map
• Simple and Easy User Interface
• Multiple Base map supports
• Ultimate Query and Analysis Tool
• Best Data security and User access control feature
• Multi roles support – Admin, Developer or Business User
• User Cloud data security is our first priority – Scalable and reliable

Looking to create maps for your store, analysis of sales data, Your real estate properties behaviour and estimates, store mapping for your customer to get into your physical store easily, Insurance companies to map disaster spatial data and predicting the premium to be costed, generating routes for your logistic business and what else. You can easily create your map with IGISMAP Analysis Cloud platform. And you can do it yourself or ask a team of our expert to help you in consulting for doing the same. You don’t need any other third part GIS Team or in house team to be expert in GIS nor require any developer who is expert with Coding skills.

Try for free – IGISMAP Analysis – Carto Alternative:

Give IGISMAP a try. Evaluate the tool for free without giving credit card details. Also contact with team of IGISMAP if you found any issues or have just an idea for creating map. We at IGISMAP will look forward to help our customer.

Here in this post we do PHP connection with pgRouting for shortest path. Here we have explained how we can add source and destination point in table and how can we query for shortest route. In this demo we have made a connection between pgrouting and PHP using code igniter using code igniter framework.
Here we have uploaded shape file in postgis. For doing this you need to  install postgres and create a database. Everything is already explained in earlier tutorial.
You can also check Postgres with QGIS.
Now the same procedure is implemented using PHP in code igniter framework. As we have an idea about code igniter, which has three main component as view, model and controller.

VIEW-

In view section  we will be adding PHP code for presenting the shapefile and the output shortest route.

Model-

In model section will be writing query for getting two end points and shortest path.

Controller-

In controller section we will make function for registration, login and distance.

First of all you need to render your shape file on map. The map can be Google map, Open street map or any other map. For rendering the shape file using leaflet you need to add plugin in your script, which can be downloaded from https://github.com/calvinmetcalf/leaflet.shapefile link. Passing shapefile in L.Shapefile() method and calling addTo(map) method we can add the shapefile on map. After that we need to create input boxes for user to enter end points latitude and longitude. Using ajax we have send these latitude and longitude of both start and end point to model and got the result back in view.

$.ajax({
type: 'POST',
url: "<?php echo base_url('index.php/User_Authentication/distance');?>",
data:{dlat1:lat1,dlong1:long1,dlat2:lat2,dlong2:long2},
dataType: 'JSON',
success: function (response) {
var data= response;
var latitude= parseFloat(response['latitude']);
var longitude= parseFloat(response['longitude']);
var geodata= GeoJSON.parse(data, {Point: ['longitude','latitude']});
geojsonLayer = L.geoJson(geodata).addTo(map);
},
error: function (errorThrown){
check_status= 0;
console.log(errorThrown);
}
});

Write Query in Model

In model section we have written an insert function, which will help us to insert the obtained latitude longitude points from user in query. The query takes latitude longitude as input. As given

insertLatLong($dlat1,$dlat2,$dlong1,$dlong2){}

Then take out the id for given source and destination point and saved them as result in variable start and end.
$start = $this->db->query("SELECT source FROM network1 ORDER BY geom <-> ST_SetSRID(ST_Point ($dlong1,$dlat1),4326) LIMIT 1")->result();
$end= $this->db->query("SELECT source FROM network1 ORDER BY geom <->  ST_SetSRID(ST_Point ($dlong2,$dlat2),4326) LIMIT 1")->result();

After completing this wrote query using pgr_dijsktra method. This is an algorithm to find out the shortest path. This takes shape file table, start point , end point, boolean result for directed/undirected route and boolean result for having/not having route cost. To get the geometry column from network table applied join. Take this result in calculation variable.
After this check for the number of row i.e. the result of query is not empty and take result in distance variable and return is to controller.

public function insertLatLong($dlat1,$dlat2,$dlong1,$dlong2) {
$calculation= $this->db->query("select seq, id1, id2, cost, geom, ST_X(ST_AsText(ST_StartPoint((ST_AsText(ST_LineMerge(ST_GeomFromText(ST_AsText(geom)))))))) as latitude, ST_Y(ST_AsText(ST_StartPoint((ST_AsText(ST_LineMerge(ST_GeomFromText(ST_AsText(geom)))))))) as longitude
from pgr_dijkstra('Select gid as id, source, target, st_length(geom::geography)/1000 as cost from network1',
$start ,$end ,false, false) as di JOIN network1 pt ON (di.id2 = pt.gid)");

if($calculation->num_rows()>0) {
$distance= $try->result();

return $distance;

} else {

return false;
}
}

Call Function in Controller

In the controller, we can call the insert function and pass the required input to called function and also can load the view. Here for this article we have made login session and registration of user. This distance function takes the data in variable in sends to insertLatLong function in Login_Database model.

public function distance() {
$dlat1 = $this->input->post('dlat1');
$dlong1 = $this->input->post('dlong1');
$dlat2 = $this->input->post('dlat2');
$dlong2 = $this->input->post('dlong2');
$res= $this->Login_Database->insertLatLong($dlat1,$dlat2,$dlong1,$dlong2);
echo json_encode($res);
}

After writing everything properly you can run the project in browser. See the shortest path as given-

Hope you enjoyed the tutorial. If you face any problem in working with pgRouting please let us know.