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R2016b Features: MarkerIndices, jsonencode, jsondecode 6

Posted by Jiro Doke,

Jiro‘s picks this week are two of the many new features of R2016b: MarkerIndices property for specifying marker locations and jsonencode/ jsondecode.

In the past, I’ve highlighted a couple of new product features which were related to previous Picks: “Interactive Legend in R 2016a” and “Does your origin go through zero?”. This week’s post is of the same nature.

MarkerIndices

Back in 2013, I posted this blog on creating line plots with fewer markers. This is especially useful when you have a dense (high-sampled) signal that you want to plot with markers. In R2016b, you can use the new MarkerIndices property to specify which points to add a marker to.

For example, if you want 10 evenly-spaced markers, you can do the following.

t  = 0:0.005:pi;
plot(t, sin(3*t).*cos(t/2), 'p-', 'MarkerIndices', round(linspace(1,length(t),10)))

jsonencode / jsondecode

In April 2015, I posted another blog on parsing JSON files. In R2016b, we now have jsonencode and jsondecode. I’ll use the same example I used in the 2015 blog post. Let’s say we have example.json the has the following content.

{
    "firstName": "John",
    "lastName": "Smith",
    "age": 25,
    "address":
    {
        "streetAddress": "3 Apple Hill Dr",
        "city": "Natick",
        "state": "MA",
        "postalCode": "01760"
    },
    "phoneNumber":
    [
        {
          "type": "home",
          "number": "123 456 7890"
        },
        {
          "type": "cell",
          "number": "098 765 4321"
        }
    ]
}

jsondecode works on character arrays, so we will first read in the text data.

str = fileread('example.json');

Then, simply call jsondecode.

data = jsondecode(str)
data = 
  struct with fields:

      firstName: 'John'
       lastName: 'Smith'
            age: 25
        address: [1×1 struct]
    phoneNumber: [2×1 struct]

The output is a structure.

disp(data.address)
    streetAddress: '3 Apple Hill Dr'
             city: 'Natick'
            state: 'MA'
       postalCode: '01760'
disp(data.phoneNumber(1))
      type: 'home'
    number: '123 456 7890'

Comments

Give these new features a try. If you’re using pre-R2016b MATLAB, be sure to check out the blog posts I mentioned above. Let us know what you think here.

Get the MATLAB code

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