On the same (lat,long) on a Tableau-Desktop map, I want the size of a dot to be proportional to the number of records at that location. I tried count/sum(Number of Records) built-in tableau measure, I created a SeqId and tried count(SeqId) for Size, neither worked. Here is a sample of my data, as you can see:
(44.92810490,-74.89186500) has one Record
(44.69948730,-73.45291240) has five Records
(44.72143010,-73.72375280) has 10 records
I would like the point to be proportional to the number of records at that location. Help is Much appreciated
Musa
Seq Id,Census,Gender,Lat,Long
1,1860,F,44.92810490,-74.89186500
2,1870,M,44.69948730,-73.45291240
3,1870,F,44.69948730,-73.45291240
4,1870,M,44.69948730,-73.45291240
5,1870,F,44.69948730,-73.45291240
6,1870,F,44.69948730,-73.45291240
7,1870,M,44.72143010,-73.72375280
8,1870,M,44.72143010,-73.72375280
9,1870,M,44.72143010,-73.72375280
10,1870,M,44.72143010,-73.72375280
11,1870,M,44.72143010,-73.72375280
12,1870,M,44.72143010,-73.72375280
13,1870,M,44.72143010,-73.72375280
14,1870,M,44.72143010,-73.72375280
15,1870,M,44.72143010,-73.72375280
16,1870,M,44.72143010,-73.72375280
Can you try this?
Create a calculated field "Geo" with this definition
IFNULL(STR([Lat]),"")+ ","+IFNULL(STR([Long],"")
Move this field in "size" mark using Count([Geo])
Hope this should give you the desired result.
Put Latitude on the Rows shelf, and then right click on the pill and convert it to a dimension. Make sure it stays continuous.
Likewise, put Longitude on the Columns shelf and convert it to a dimension
Put SUM(Number of Records) on the size shelf
Important, Don't have any other dimensions on any shelves, leave SeqId off
This approach will make one mark for each unique latitude/longitude pair and size that mark according to how many times that pair appears in the data set.
A problem you will probably notice is that two latitudes that differ only in the final decimal place are treated as distinct latitudes. That may not make the most useful visualization. You can bin nearby latitudes together by making a calculated field to round values to the degree you wish. If you do that, be sure to make your field a continuous dimension, and also set its geographic role. It has the effect of snapping lat/long pairs to a grid. As an alternative to rounding, you can look into the hexbinx() and hexbiny() functions.
For a heat map based on square or hex grids, you may want to try using (partially transparent) colors instead of size to indicate density.
Some plot points in my dataset need to be highlighted. Ideally I would like to be able to do the following:
Id like to display arbitary HTML at a particular X location (with a Y of my choosing)
Id like to replace certain markers with HTML
Is this possible? I cannot seem to find any documentation on how to do it?
Is there any way to search for items within distance of a lat/long for multiple lat/longs simultaneously? E.g., to say "give me all results within 10 miles of 14.2342,-13.234234 AND 1.3234,4.56775"?
I currently only see the ability to search one set of coordinates at a time.
In its current version, the API only allows to pass one lat/long value at a time.
Nevertheless, it allows to pass multiple bounding boxes at the same time. That means that you could easily calculate the bounding boxe coordinates (see How to calculate the bounding box for a given lat/lng location?), and pass those to the search parameters.
You can find here https://www.algolia.com/doc/tutorials/geo-search a guide (+ sample code) showing how Geoloc search works. And more detail about the boundingBox parameters at https://www.algolia.com/doc/rest#param-insideBoundingBox
I'm following this tutorial
The goal is to be able to spit out either:
a. the center of each labeled object
b. all pixels associated with each labeled object
in a way that I have an array of either 'a.' for each object, or 'b.' for each object
I'm really not sure how to go about this. Are there matlabl tools to help extract these set of pixels or centers - per - label?
Update
I did manage to circle 80% of what I wanted using reigionprops, however it doesn't capture label precisely, just sets a circle around them while capturing the background as well, is that really unavoidable? I'm just not sure how to access the set of pixel per each circled item.
r=regionprops(L, 'All'); imshow(imagergb); areas={r.Area}; Bboxes={r.BoundingBox};
for k=2:numel(r)
if areas{k}>50 && areas{k} < 1100
rectangle('Position',Bboxes{k}, 'LineWidth',1, 'EdgeColor','b', 'Curvature', [1 1]);
end
end
So what I'm trying to do is for example.
I thought it might just be
r = regionprops(L, 'PixelIdxList')
then
element1 = r(1).PixelIdxList
but couldn't figure out how to get the position of each pixel
I also tried
Z= bwlabel(L);
but imshow(Z==1) spits out all labels and imshow(Z==2) spits out background, all labels and background. couldn't test bwlabeln since I'm not exactly sure what to enter for r and c arguments.
Using regionprops(L, 'PixelIdxList') is correct. It gives you lists of pixel indices for each label. You can then convert them to [x,y] coordinates using (for the first label, for example)
[y,x] = ind2sub(size(L), r(1).PixelIdxList)
You can get label centers by using regionprops(L, 'Centroid'). This already gives you [x,y] coordinates for each label. Note that these are subpixel coordinates, so you may need to round them if you want to use them as indices.
I am creating a map in which i want a polygon to display two separate variables within it. Therefore I want a stripped polygon relating to both the keys from the separate factors however I have no idea on how to do this. I messed around with multiple attributes on the properties section and could get the two variables up however could see no way of making the polygon display them both.
Thank you, any help would be appreciated
This is partially manual, but you are going to have to make a separate category within one of the fields that identifies the multivariate features. You could also create a new layer that is a selection of these features. Once you have that, go to the layer properties and display the features as 'Categories - Unique values, many fields' and hit the 'Add All Values' button. Once the categories are populated select the one you are interested in and pick a hatched symbol such as 'Radiation Overlay'. Then go to the Symbol Property Editor (double-click the symbol) and modify the two layers that make up the hatched symbol. You need to adjust the color, line thickness, offset, etc. until you get it to look the way you want. Probably not as auto as you wanted, but it will satisfy display purposes.