MATLAB: Retrieving data from structures

periodic tablestructure

I am working on a function for the periodic table that when I input a property and group number, the output is the requested property of the atom belonging to the requested group number. I have already created a structure for the first 18 elements that I know works. It holds the properties: atomic number, group, period, and symbol.

If I have: function periodictable(property,groupnumber), how would I be able to extract the data…if that makes sense.

Example:

>> periodictable('symbol',2) ans = 'Be' 'Mg'

>> periodictable('atomicnumber',1) ans = [1] [3] [11]

Best Answer

I'm assuming you have a structure array, yourstruct, and that yourstruct(i) corresponds to the i-th element.

 idx=[yourstruct.group]==number_to_search;
 out = {yourstruct(idx).(property)};

Related Solutions

MATLAB: Write a function that returns the requested property of atoms belonging to the requested groupnumber

Pretty close, but try it like this:

function test
% Main test harness to call the function.
results = periodictable(6) % Ask for Carbon.
function [ output_args ] = periodictable(atomicNumber)
%that returns the requested property of atoms belonging to the requested 
%groupnumber. Consider only the first 18 atoms in the periodic table (i.e., 
%up to and including Argon). Inside your function, store the periodic table 
%of elements as a structure array. Store the atomicnumber, group, period,
%and symbol for each atom.
p = struct('symbol', {'H' 'He' 'Li' 'Be' 'B' 'C' 'N'...
  'O' 'F' 'Ne' 'Na' 'Mg' 'Al' 'Si' 'P' 'S' 'Cl' 'Ar'}, ...
  'atomicnumber', {1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18}, ...
  'period', {1 1 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3}, ...
  'group', {1 18 1 2 13 14 15 16 17 18 1 2 13 14 15 16 17 18});
if atomicNumber > length(p)
  uiwait(warndlg('Enter a number less than or equal to 18'));
  output_args = [];
  return;
end
output_args.symbol = p(atomicNumber).symbol;
output_args.atomicnumber = p(atomicNumber).atomicnumber;
output_args.period = p(atomicNumber).period;
output_args.group = p(atomicNumber).group;

MATLAB: Making structure arrays programmtically.

If you have the stats TB you can import a file directly as a dataset object.

It is very convenient and easy to use.

EDIT

I have created the following xlsx file:

Now to create programmatically the structure (independently on the number of columns):

[data,text] = xlsread('test.xlsx');
In = [text;num2cell(data,1)];
S  = struct(In{:});

Or if you want a non-scalar structure create first In as:

In = [text;num2cell(num2cell(data),1)];

Best Answer

Related Solutions

MATLAB: Write a function that returns the requested property of atoms belonging to the requested groupnumber

MATLAB: Making structure arrays programmtically.

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