Difference between revisions of "QGIS/C2/Coordinate-Reference-Systems/English"
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'''Title Slide''' | '''Title Slide''' | ||
− | || Welcome to this tutorial on '''Coordinate Reference System '''in''' QGIS'''. | + | || Welcome to this tutorial on '''Coordinate Reference System''' in ''' QGIS'''. |
|- | |- | ||
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|| In this tutorial, we will learn to, | || In this tutorial, we will learn to, | ||
− | *Add layers to '''projections''' in '''QGIS'''. | + | * Add layers to '''projections''' in '''QGIS'''. |
− | *View '''metadata''' information for '''layers'''. | + | * View '''metadata''' information for '''layers'''. |
− | *Save selected features from a '''layer''' to a new '''layer'''. | + | * Save selected features from a '''layer''' to a new '''layer'''. |
− | *Re-project and overlay '''data layers''' of different '''projections''' together. | + | * Re-project and overlay '''data layers''' of different '''projections''' together. |
|- | |- | ||
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|| To record this tutorial I am using, | || To record this tutorial I am using, | ||
− | *'''Ubuntu Linux OS '''version | + | * '''Ubuntu Linux OS''' version 16.04 |
− | *'''QGIS''' version 2.18 | + | * '''QGIS''' version 2.18 |
|- | |- | ||
Line 37: | Line 37: | ||
'''Pre-requisites''' | '''Pre-requisites''' | ||
− | *'''Basic knowledge about GIS | + | * '''Basic knowledge about GIS'''. |
− | *Please view pre-requisite tutorial in this series. | + | * Please view pre-requisite tutorial in this series. |
− | || To follow this tutorial you should have basic knowledge about '''GIS | + | || To follow this tutorial you should have basic knowledge about '''GIS'''. |
− | + | ||
Please view previous tutorial in this series. | Please view previous tutorial in this series. | ||
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'''Coordinate Reference systems''' | '''Coordinate Reference systems''' | ||
|| About '''Coordinate Reference Systems''', | || About '''Coordinate Reference Systems''', | ||
− | |||
'''Coordinate Reference Systems''' are of two types, | '''Coordinate Reference Systems''' are of two types, | ||
− | *'''Geographic coordinate system''' | + | * '''Geographic coordinate system''' |
− | *'''Projected Coordinate System''' | + | * '''Projected Coordinate System''' |
|- | |- | ||
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'''Coordinate Reference systems''' | '''Coordinate Reference systems''' | ||
− | ||Most widely used '''geographic coordinate system''' is '''WGS 84 | + | ||Most widely used '''geographic coordinate system''' is '''WGS 84'''. |
Most widely used '''projected coordinate system''' is '''UTM'''. | Most widely used '''projected coordinate system''' is '''UTM'''. | ||
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|- | |- | ||
|| Click on '''QGIS''' icon to open the interface. | || Click on '''QGIS''' icon to open the interface. | ||
− | |||
Cursor on Canvas. | Cursor on Canvas. | ||
|| Here I have opened '''QGIS''' interface. | || Here I have opened '''QGIS''' interface. | ||
− | |||
On the '''canvas''', world map with country administration boundaries is displayed. | On the '''canvas''', world map with country administration boundaries is displayed. | ||
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'''World Map File''' | '''World Map File''' | ||
|| Demonstration on how to download the map and display in '''QGIS''' is explained in the prerequisite tutorial. | || Demonstration on how to download the map and display in '''QGIS''' is explained in the prerequisite tutorial. | ||
− | |||
Please view the pre-requisite tutorial. | Please view the pre-requisite tutorial. | ||
− | |||
This file can also be downloaded from the '''Code files''' link. | This file can also be downloaded from the '''Code files''' link. | ||
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|| By default '''Layers Panel''' is enabled here. | || By default '''Layers Panel''' is enabled here. | ||
− | + | If not, we can enable or disable the '''Layers Panel''' using '''View''' menu. | |
− | If not, we can enable or disable the '''Layers Panel '''using '''View''' menu. | + | |
|- | |- | ||
|| Click on '''View''' tool on the Tool bar. | || Click on '''View''' tool on the Tool bar. | ||
− | |||
− | |||
− | |||
|| Click on '''View''' menu on the '''menu''' bar. | || Click on '''View''' menu on the '''menu''' bar. | ||
− | |||
Scroll down and select '''Panels '''option. | Scroll down and select '''Panels '''option. | ||
|- | |- | ||
− | || Scroll down and select '''Panels '''option. | + | || Scroll down and select '''Panels''' option. |
From the sub-menu, click on '''Layer Panel'''. | From the sub-menu, click on '''Layer Panel'''. | ||
|| Sub-menu shows a list of '''panel''' names. | || Sub-menu shows a list of '''panel''' names. | ||
− | |||
Click on '''Layer Panel''' option to enable or disable the '''panel'''. | Click on '''Layer Panel''' option to enable or disable the '''panel'''. | ||
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|- | |- | ||
|| Right-click on the layer name in''' Layers Panel.''' | || Right-click on the layer name in''' Layers Panel.''' | ||
− | |||
− | |||
|| If you wish to change the color of the map, right-click on the '''layer''' name in the '''Layers Panel.''' | || If you wish to change the color of the map, right-click on the '''layer''' name in the '''Layers Panel.''' | ||
|- | |- | ||
− | || Scroll-down the '''context menu''' | + | || Scroll-down the '''context menu''' >> select '''Styles''' option. |
|| Scroll-down the '''context menu''' and select '''Styles''' option. | || Scroll-down the '''context menu''' and select '''Styles''' option. | ||
|- | |- | ||
||Rotate the vertex of the color triangle to choose the color. | ||Rotate the vertex of the color triangle to choose the color. | ||
− | |||
− | |||
||Sub-menu shows a color triangle . | ||Sub-menu shows a color triangle . | ||
− | |||
Choose the color by rotating the vertex of the color triangle. | Choose the color by rotating the vertex of the color triangle. | ||
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|- | |- | ||
− | || Cursor on''' Coordinate label '''and text box. | + | || Cursor on''' Coordinate label ''' and text box. |
− | + | ||
− | + | ||
− | + | ||
|| At the bottom-left corner, on the '''status''' bar of '''QGIS''' window, you will notice | || At the bottom-left corner, on the '''status''' bar of '''QGIS''' window, you will notice | ||
− | *the label '''Coordinate ''' | + | * the label '''Coordinate ''' |
− | *and a text box with numbers. | + | * and a text box with numbers. |
|- | |- | ||
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|- | |- | ||
|| Move the cursor over the map. | || Move the cursor over the map. | ||
− | |||
Point | Point | ||
|| Move the cursor over the map. | || Move the cursor over the map. | ||
− | |||
Observe, that the values of '''X''' and '''Y coordinates''' change with the location of the cursor. | Observe, that the values of '''X''' and '''Y coordinates''' change with the location of the cursor. | ||
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|- | |- | ||
− | || Point towards '''EPSG:4326(OTF) ''' | + | || Point towards '''EPSG:4326(OTF) ''' at the bottom-right corner of the status bar. |
− | || On the '''status bar''', at the bottom-right corner, you will see another ''' | + | || On the '''status bar''', at the bottom-right corner, you will see another label, '''Current CRS''' |
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|- | |- | ||
|| From the context menu, select '''Properties'''. | || From the context menu, select '''Properties'''. | ||
− | |||
− | |||
|| From the context menu, select '''Properties'''. | || From the context menu, select '''Properties'''. | ||
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|- | |- | ||
|| Point to heading, '''Layer Spatial Reference System.''' | || Point to heading, '''Layer Spatial Reference System.''' | ||
− | |||
Point to '''WGS84'''. | Point to '''WGS84'''. | ||
− | |||
− | |||
− | |||
|| At the bottom, | || At the bottom, | ||
*under heading, '''Layer Spatial Reference System,''' | *under heading, '''Layer Spatial Reference System,''' | ||
*you will see the definition for this projection. | *you will see the definition for this projection. | ||
− | |||
It shows '''WGS84 '''as '''geographic coordinate system.''' | It shows '''WGS84 '''as '''geographic coordinate system.''' | ||
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|| About '''data layers'''. | || About '''data layers'''. | ||
− | *Usually '''geographical data''' is stored in '''layers''' in a '''GIS''' workspace. | + | * Usually '''geographical data''' is stored in '''layers''' in a '''GIS''' workspace. |
− | *Each '''layer''' has '''data''' stored in its '''attribute table'''. | + | * Each '''layer''' has '''data''' stored in its '''attribute table'''. |
− | *Many '''layers''' can represent '''data''' of the same geographical location. | + | * Many '''layers''' can represent '''data''' of the same geographical location. |
|- | |- | ||
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− | This operation is called '''Re-Projection | + | This operation is called '''Re-Projection'''. |
− | + | ||
Instead of re-projecting the entire '''layer''', we will re-project some features. | Instead of re-projecting the entire '''layer''', we will re-project some features. | ||
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− | Note that, the''' United States of America '''is shown in a different color. | + | Note that, the '''United States of America''' is shown in a different color. |
|- | |- | ||
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|- | |- | ||
|| '''Save Vector Layer as '''dialog box opens. | || '''Save Vector Layer as '''dialog box opens. | ||
− | |||
− | |||
− | |||
|| '''Save Vector Layer as... '''dialog box opens. | || '''Save Vector Layer as... '''dialog box opens. | ||
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|- | |- | ||
|| Click on '''Browse''' button. | || Click on '''Browse''' button. | ||
− | || Click on '''Browse button '''next to '''File name '''text box. | + | || Click on '''Browse button''' next to '''File name '''text box. |
|- | |- | ||
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|- | |- | ||
|| Click select '''CRS''' button next to '''CRS''' text box. | || Click select '''CRS''' button next to '''CRS''' text box. | ||
− | |||
− | |||
− | |||
|| We will choose the new '''projection''' for this '''layer'''. | || We will choose the new '''projection''' for this '''layer'''. | ||
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|- | |- | ||
|| In the '''Coordinate Reference System Selector''' dialog box, type '''North America''' | || In the '''Coordinate Reference System Selector''' dialog box, type '''North America''' | ||
− | |||
− | |||
|| | || | ||
− | *In the '''Coordinate Reference System Selector''', | + | * In the '''Coordinate Reference System Selector''', |
− | *In the '''Filter search box''', enter '''North America''' | + | * In the '''Filter search box''', enter '''North America''' |
|- | |- | ||
|| Click '''North_America_Albers_Equal_Area_Conic''' | || Click '''North_America_Albers_Equal_Area_Conic''' | ||
− | |||
− | |||
− | |||
|| | || | ||
− | *Under '''Coordinate reference systems''' of the world, | + | * Under '''Coordinate reference systems''' of the world, |
− | *Under heading '''Projected Coordinate System, ''' | + | * Under heading '''Projected Coordinate System, ''' |
− | *Scroll through the results. | + | * Scroll through the results. |
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|- | |- | ||
− | || Cursor on , '''Add saved file to map | + | || Cursor on , '''Add saved file to map'''. |
|| Here, by default, '''Add saved file to map '''option is checked. | || Here, by default, '''Add saved file to map '''option is checked. | ||
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|- | |- | ||
− | || | + | || uncheck enable '''on the fly CRS transformation''' |
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− | The '''projection''' text at the bottom-right of '''QGIS''' window has the words, '''OTF '''next to '''EPSG:4326'''. | + | The '''projection''' text at the bottom-right of '''QGIS''' window has the words, '''OTF''' next to '''EPSG:4326'''. |
|- | |- | ||
|| At the bottom-right corner, click on '''EPSG:4326'''. | || At the bottom-right corner, click on '''EPSG:4326'''. | ||
− | |||
− | |||
− | |||
|| Select '''United-States''' layer in the '''Layers Panel '''by clicking on it. | || Select '''United-States''' layer in the '''Layers Panel '''by clicking on it. | ||
− | |||
Click on the '''Current CRS''' text, '''EPSG:4326,''' at the bottom-right corner of the '''status''' bar. | Click on the '''Current CRS''' text, '''EPSG:4326,''' at the bottom-right corner of the '''status''' bar. | ||
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|- | |- | ||
|| Uncheck '''Enable on the fly CRS transformation '''check box, | || Uncheck '''Enable on the fly CRS transformation '''check box, | ||
− | |||
− | |||
− | |||
|| Uncheck '''Enable on the fly CRS transformation '''check box, by clicking on it. | || Uncheck '''Enable on the fly CRS transformation '''check box, by clicking on it. | ||
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− | You can see only '''United States''' map on the '''canvas'''. | + | You can see only the'''United States''' map on the '''canvas'''. |
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|- | |- | ||
|| Right-click on USA-1.shp in Layers panel. | || Right-click on USA-1.shp in Layers panel. | ||
− | |||
− | |||
|| To delete the '''vector layer''' from the '''dataset''', right-click on the name in '''Layers panel'''. | || To delete the '''vector layer''' from the '''dataset''', right-click on the name in '''Layers panel'''. | ||
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* Add '''layers''' to '''projections''' in '''QGIS'''. | * Add '''layers''' to '''projections''' in '''QGIS'''. | ||
+ | |||
* View '''metadata''' information for '''layers'''. | * View '''metadata''' information for '''layers'''. | ||
+ | |||
* Save selected '''features''' from a '''layer''' to a new '''layer'''. | * Save selected '''features''' from a '''layer''' to a new '''layer'''. | ||
+ | |||
* '''Re-project''' and '''overlay data layers''' of different '''projections''' together. | * '''Re-project''' and '''overlay data layers''' of different '''projections''' together. | ||
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|| As an Assignment: | || As an Assignment: | ||
− | *'''Project''' The '''United States '''with '''North_America_Lambert_Conformal_Conic projection''' | + | * '''Project''' The '''United States '''with '''North_America_Lambert_Conformal_Conic projection''' |
− | *and observe the difference. | + | * and observe the difference. |
− | *'''Re-project''' the entire world map '''layer''' into '''World Mercator projection''' system. | + | * '''Re-project''' the entire world map '''layer''' into '''World Mercator projection''' system. |
|- | |- | ||
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||The video at the following link summarizes the Spoken Tutorial project. | ||The video at the following link summarizes the Spoken Tutorial project. | ||
Please download and watch it. | Please download and watch it. | ||
− | |||
− | |||
− | |||
|- | |- | ||
|| '''Slide Number 13''' | || '''Slide Number 13''' | ||
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− | Do you have questions in THIS Spoken Tutorial? | + | * Do you have questions in THIS Spoken Tutorial? |
− | + | * Please visit this site | |
− | + | * Choose the minute and second where you have the question | |
− | + | * Explain your question briefly | |
− | + | * Someone from our team will answer them | |
Line 598: | Line 548: | ||
Thank you for joining | Thank you for joining | ||
− | + | |- | |
|} | |} |
Revision as of 16:39, 30 August 2018
Visual Cue | Narration |
Slide Number 1
Title Slide |
Welcome to this tutorial on Coordinate Reference System in QGIS. |
Slide Number 2
Learning Objectives |
In this tutorial, we will learn to,
|
Slide Number 3
System Requirement |
To record this tutorial I am using,
|
Slide Number 4
Pre-requisites
|
To follow this tutorial you should have basic knowledge about GIS.
Please view previous tutorial in this series. |
Slide Number 5
Coordinate Reference systems |
About Coordinate Reference Systems,
Coordinate Reference Systems are of two types,
|
Slide Number 5
Coordinate Reference systems |
Most widely used geographic coordinate system is WGS 84.
Most widely used projected coordinate system is UTM. |
Click on QGIS icon to open the interface.
Cursor on Canvas. |
Here I have opened QGIS interface.
On the canvas, world map with country administration boundaries is displayed. |
Slide Number 6
World Map File |
Demonstration on how to download the map and display in QGIS is explained in the prerequisite tutorial.
Please view the pre-requisite tutorial. This file can also be downloaded from the Code files link. |
Cursor on layers panel on name of the map file. | On the left-side of the canvas, you will see Layers Panel, with file name of the world map as a layer. |
Cursor on the canvas. | By default Layers Panel is enabled here.
If not, we can enable or disable the Layers Panel using View menu. |
Click on View tool on the Tool bar. | Click on View menu on the menu bar.
Scroll down and select Panels option. |
Scroll down and select Panels option.
From the sub-menu, click on Layer Panel. |
Sub-menu shows a list of panel names.
Click on Layer Panel option to enable or disable the panel. |
Drag the boundary with the mouse. | We can adjust the size of the panel by dragging the boundary. |
Right-click on the layer name in Layers Panel. | If you wish to change the color of the map, right-click on the layer name in the Layers Panel. |
Scroll-down the context menu >> select Styles option. | Scroll-down the context menu and select Styles option. |
Rotate the vertex of the color triangle to choose the color. | Sub-menu shows a color triangle .
Choose the color by rotating the vertex of the color triangle. |
Click anywhere on the canvas. | Click anywhere on the canvas to close the context menu. |
Cursor on Coordinate label and text box. | At the bottom-left corner, on the status bar of QGIS window, you will notice
|
Highlight X and Y coordinates. (Editing stage) | Values of X and Y coordinates for a particular location are shown in this text box. |
Move the cursor over the map.
Point |
Move the cursor over the map.
Observe, that the values of X and Y coordinates change with the location of the cursor. |
Cursor on Render option. | By default Render option is checked on the status bar.
|
Point towards EPSG:4326(OTF) at the bottom-right corner of the status bar. | On the status bar, at the bottom-right corner, you will see another label, Current CRS
|
To determine a layer’s projection, we can look into the metadata. | |
Right click on the Layers Panel, ne_10m_admin_0_countries | On the Layers Panel, right-click on the layer name. |
From the context menu, select Properties. | From the context menu, select Properties.
|
Click on Metadata option in Layer dialog-box.
Scroll down. |
In the dialog-box, on the left-side panel, click on Metadata option.
|
Point to heading, Layer Spatial Reference System.
Point to WGS84. |
At the bottom,
It shows WGS84 as geographic coordinate system. |
Click Ok button | Click on Ok button at the bottom, to close the dialog box. |
Let us now add layers to the map and change the projection. | |
Slide Number 7
Data layers |
About data layers.
|
Back to the QGIS interface. | |
Cursor on the QGIS canvas. | Now let us see how we can change the layer’s projection.
Instead of re-projecting the entire layer, we will re-project some features. |
On top-right corner of the tool bar >> click on Select features by area or single click tool. | On top-right corner of the tool bar, click on Select features by area or single click tool. |
Click on the black triangle next to this tool. | Click on the black triangle next to this tool. |
Drop down >> choose Select features. | From the drop down choose Select features. |
On the canvas, on the world map, click on United States of America. | On the world map displayed on canvas, click on the United States of America feature to select it.
|
Cursor on the map. | We will now change the projected coordinate system of this layer and save. |
Right click on ne_10m_admin_0_countries | Right-click on the layer name in the Layers Panel. |
Click on Save As option | Scroll down, select Save As option. |
Save Vector Layer as dialog box opens. | Save Vector Layer as... dialog box opens.
Leave it as such. |
Click on Browse button. | Click on Browse button next to File name text box. |
Save layer as... dialog-box opens.
In the name text box, type the layer as USA-1.shp. |
Save layer as... dialog-box opens.
|
Click on Desktop option.
|
Find a suitable location to save.
I will save it on Desktop Click on Save button at the bottom. |
In the Save Vector Layer as... dialog-box.
|
In the Save Vector Layer as.... dialog-box, the file path appears in the File name text box. |
Click select CRS button next to CRS text box. | We will choose the new projection for this layer.
|
In the Coordinate Reference System Selector dialog box, type North America |
|
Click North_America_Albers_Equal_Area_Conic |
|
Click on OK button. | Click on OK button at the bottom. |
In the Save vector layer as... dialog-box, cursor on CRS drop down box. | In the CRS drop down box, the newly selected CRS is shown. |
In the Save Vector Layer as dialog-box,
|
Click on the check box to check Save only selected features option.
|
Cursor on , Add saved file to map. | Here, by default, Add saved file to map option is checked.
|
In the Save Vector Layer as... dialog-box, click on OK button | Click on OK button at the bottom. |
Point on united states outline.
|
The re-projected layer gets loaded, in a different color.
|
uncheck enable on the fly CRS transformation
|
Notice that the new United States layer overlays perfectly on top of the world map layer.
|
At the bottom-right corner, click on EPSG:4326. | Select United-States layer in the Layers Panel by clicking on it.
Click on the Current CRS text, EPSG:4326, at the bottom-right corner of the status bar. |
Cursor on Project Properties CRS dialog-box. | Project Properties CRS dialog-box opens.
|
Uncheck Enable on the fly CRS transformation check box, | Uncheck Enable on the fly CRS transformation check box, by clicking on it.
|
Cursor on the map. | Back in the main QGIS window, you will see the world map disappear.
|
Right click on USA-1.shp layer.
|
The coordinates and scale are different now.
|
Click on EPSG
|
Again, click on the Current CRS text to open Project Properties dialog-box.
|
Under the heading Recently used Coordinate Reference Systems, select WGS 84.
|
Under the heading Recently used Coordinate Reference Systems, select WGS 84.
At the bottom, click on the OK button.
|
Right-click on USA-1.shp in Layers panel. | To delete the vector layer from the dataset, right-click on the name in Layers panel. |
Click on Remove option from the context menu.
|
From the context menu, click on Remove option.
Click on OK button. |
Cursor on the layers panel. | Observe that the layer is removed from the dataset. |
Slide Number 10
Summary |
Let us summarize,
In this tutorial we have learnt to
|
Slide Number 11
Assignment |
As an Assignment:
|
Show completed assignments. | Your completed assignment should look like this. |
Slide Number 12
About Spoken Tutorial project |
The video at the following link summarizes the Spoken Tutorial project.
Please download and watch it. |
Slide Number 13
Spoken Tutorial workshops |
The Spoken Tutorial Project team:
conducts workshops using spoken tutorials and gives certificates on passing online tests. For more details, please write to us. |
Slide number 14
Forum for specific questions:
|
Please post your timed queries on this forum. |
Slide Number 16:
Acknowledgement |
Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India.
More information on this mission is available at this link. |
This tutorial is contributed by Prajwal. M from Sahyadri college of Engineering and Snehalatha from IIT Bombay.
Thank you for joining |