# Create continuous raster from point values in 10.1?

I have a point dataset of nearly 400 points containing percentage values the point is representing

Is there a way to create a smooth continuous raster surface across the whole of the UK of the point values? I have tried using Feature to raster and point to raster and I get similar results of the points being surrounded by the raster square cell in a certain colour depending upon the value. What I am looking for is raster covering the whole of the uk so most of it will be zero where there is no data or no points and the same colour and then then where the point values are they go up in colour showing the difference in values.

I have used kernel density before but I don't particularly want the raster create using magnitude of points near each other.

• Better you post the screenshot and make it more clear :) – SIslam Jul 22 '16 at 11:45

Because a raster is continuous and points are discrete, you will need to use an interpolation method to create the kind of raster you would like. There are several different interpolation methods that may be better or worse for a specific application - but, here is a pretty brief overview of interpolation: http://pro.arcgis.com/en/pro-app/tool-reference/3d-analyst/understanding-interpolation-analysis.htm

And here is a brief overview of the different interpolation methods offered in ArcMap: http://pro.arcgis.com/en/pro-app/tool-reference/3d-analyst/comparing-interpolation-methods.htm.

Once you have interpolated a raster surface, you can clip to the UK boundary.

If I get you correctly, You need to use the below steps-

1. Use point to raster, it will give you a raster of points but blank where no points(i.e. NoData area rendered with nocolor)- maintain same pixel size with layer 2 e.g. 5*5
2. To get the background, convert polygon of UK into raster after setting the value for this layer 0- maintain same pixel size with layer 1 e.g. 5*5

Now there are ways to go- one of them: Use Raster Calculator to add (just getting the extent of the UK area, adding zero does to affect at all) above two raster setting processing extent(in the Environment setting) to the larger one(UK boundary polygon raster) and after that use Reclassify tool to assign zero(or what you want) to the NoData values- that's all.

N.B. It will give you a rectangular raster area- if you want clip the raster by the UK boundary polygon.

• Wouldn't interpolation create values where my point values aren't – Jonathan Hallam Jul 22 '16 at 11:42
• OK edited the answer :) – SIslam Jul 25 '16 at 9:54

If I understand your question, you want the same result you get from PointToRaster, but you'd prefer to have zeroes in all the NoData cells? Simply follow PointToRaster with Spatial Analyst > Reclassify, converting the NoDatas to zero and the data values to whatever makes sense for your project. Then set the symbology to get the visual contrast you are looking for. (Without Spatial Analyst, you could just change the symbology and give NoData a background color instead, depending on what further uses you will have for the layer.)

• Yes it will work if the points are all over the UK. But if all points are inside a city then it will not work rather it will create envelop of those points- since he needs all the UK as background. – SIslam Jul 22 '16 at 15:37
• I don't quite understand your comment? Can't he clip the raster to the UK or overlay a UK outline? – J Kelly Jul 22 '16 at 15:39
• AH! No overlay he only needs one single raster layer! Say all of his points inside London but he wants a raster layer of whole UK where those points have respective value and the other e.g. South Wales have 0 value but Point To Raster operation will just create a raster around London Not The Other Cities!!. – SIslam Jul 22 '16 at 15:40
• Ok, so raster clip. – J Kelly Jul 22 '16 at 15:40
• One has much control over a reclass operation. If the points layer was one layer to begin with and the new raster has, say 20 values in London and one point in South Wales with actual field value zero, he can easily change NoData to zero and then bump up the other values, say by an increment of 0.1 or into range-classes. Or, as I suggested, just leave the NoDatas and set a background color. Perhaps @Jonathan Hallam can clarify. Is your concern the raster will be too coarse and conflate nearby points into one cell? – J Kelly Jul 22 '16 at 15:48