Borrar filtros
Borrar filtros

How to Get one Property of a Structure Array Using a Property on the Same Line

5 visualizaciones (últimos 30 días)
Hello all,
I'm a novice at MatLab (I'm taking a course on it), but I want to use it to be able to access atomic masses without needing to look at the back of my back for a course. I found a CSV of the atomic masses of every isotope, and I've made it into a structure array using a for loop. Basic stuff.
rawMassData = readcell('IUPAC-atomic-masses.csv');
for i=3:length(rawMassData)
isotopicMasses(i).name = rawMassData{i,1};
isotopicMasses(i).mass = rawMassData{i,2};
isotopicMasses(i).uncertainty = rawMassData{i,3};
end
The question I have is how do I now get the mass of a certain isotope? One field in the structure array is all the names, so I should just be able to index into the structure by name, find the line that that isotope is on, and get the mass on that same line right? I just don't know how to do that.

Respuesta aceptada

Voss
Voss el 14 de Abr. de 2024
name = 'deuterium'; % name of the isotope you want the mass of
idx = strcmp({isotopicMasses.name},name);
mass = isotopicMasses(idx).mass;
  2 comentarios
Tom
Tom el 14 de Abr. de 2024
Thank you! This was exactly what I was looking for.
Voss
Voss el 14 de Abr. de 2024
Editada: Voss el 14 de Abr. de 2024
You're welcome! Any questions, let me know.

Iniciar sesión para comentar.

Más respuestas (1)

Steven Lord
Steven Lord el 14 de Abr. de 2024
You could do what you described by making a non-scalar struct, each element of which has three fields, each of which has a piece of text or a number. Another approach would be to create a scalar struct, each field of which is named for an element, and which contains a struct.
elements.carbon = struct('number', 6, 'mass', 12.011)
elements = struct with fields:
carbon: [1x1 struct]
elements.carbon
ans = struct with fields:
number: 6 mass: 12.0110
Since you're reading the data from a file, you'd need to use dynamic field names to create the field.
name = 'oxygen';
elements.(name) = struct('number', 8, 'mass', 15.999)
elements = struct with fields:
carbon: [1x1 struct] oxygen: [1x1 struct]
Alternately, since your data is tabular in nature, consider creating it as a table array rather than a struct.
names = ["carbon"; "oxygen"];
number = [6; 8];
mass = [12.011; 15.999];
elementsT = table(number, mass, RowNames = names)
elementsT = 2x2 table
number mass ______ ______ carbon 6 12.011 oxygen 8 15.999
To retrieve the data, you can use curly braces or dot notation.
elementsT{'carbon', 'mass'}
ans = 12.0110
allMasses = elementsT.mass
allMasses = 2x1
12.0110 15.9990
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>

Categorías

Más información sobre Programming en Help Center y File Exchange.

Etiquetas

Productos


Versión

R2024a

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by