Need help displaying Dictionary into Tableview

App Development
1

Hey guys, I’m designing an app that analyzes data from the accelerometer from the phone.
What I’m trying to do is display that data collected into a a tableview. The basic outline is that it sampling data every 0.2sec and should display the data into sections (each section is a second) with 5 rows (each row is the sampled data every 0.2sec)

What I am trying to display is that each section is labeled the appropriate second and in each section showing the accelerometer data (Z axis):

Each row is the accelerometer data collected a every 0.2sec (hence each section is 0.2sec * 5)

What I thought would work is take the data and store it into an array. I’m having trouble breaking up the data for display.

I then created a dictionary or arrays where each key is the “second” and the values are an array of the accelerometer data for that second. My thinking was that I could label each section based on the key and display the values for that key into the rows but I’m stuck and not sure if that was the right approach.

I tried storing the keys and values into arrays in my tableview controller using keys = acceldata.keys but can extract the values as individual elements of that array.

ex.

acceldata[1] : [0.2, 0.4, 0.6, 0.8, 1.0]

acceldata[2] : [-0.2, -0.4, -0.6, 0.8, -1.0]

How I would like for it to be displayed:

second 1

  • 0.2
  • 0.4
  • 0.6
  • 0.9
  • 1.0

second 2

  • -0.2
  • -0.4
  • -0.6
  • -0.8
  • -1.0

I am not sure if this logic was correct or if there is another way of doing this. Any advice would be helpful. Should I stick with the dictionary method? My hope was that I could use each key as the title for the section and value for that key as the data source for the rows.

2

I figured it out…

3

Please post your solution!!!
It may help someone else

4

To display the values from the dictionary:

In the cellForRow method to display the individual cell

let cellDisplay = acceldata[indexPath.section]?[indexPath.row]
cell.cellDisplay?.text = "\(cellDisplay)"
return cell

This translates as:

access the first section then each element in the array in the value of that key

so acceldata[1] = [[0.2, 0.4, 0.6, 0.8, 1.0] would translate as the following to display:

indexPath.section = 1
indexPath.row = 0 would be 0.2, 1 = 0.4 and so on.

To display the keys - it was a little more involved.

First I had to store the value of the keys into an array into a separate function

arrayOfNumberOfKeys = Array(acceldata.keys)

This stored the keys into an array so I could access each element to display as the section header.

In the function titleForHeaderInSection - I called the above method and returned the value into a string

override func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
    configureNumberOfSectionsForDisplay()
    
    return String("Second \(arrayOfNumberOfKeys[section]+1)")
}

I added the +1 one because the first section is to be data for the first second.

Hope that is helpful!