Import Excel and plot

Hie everyone, i face some problems that i do not actually know where is the problem is. Let's say i have an excel file with two columns. First is 'frequency' and second column is 'data'. When i import the excel file into my GUI, i put two popupmenu two choose for y-axis and x-axis. The problems is, the popupmenu only manage to shows the frequency, for both axis, but not the data. However, when i click the blank space below the frequency which is suppose to be the data words, it manage to plot the graph. So i want to ask, how can i make the data words appear in the popupmenu. Below is the code for my GUI. Regards, Ean

handles.fileName=uigetfile('*.xls') guidata(hObject,handles) setPopupmenuString(handles.popupmenuX,eventdata,handles) setPopupmenuString(handles.popupmenuY,eventdata,handles) set(handles.popupmenuX,'callback','maingui(''updateAxes'',gcbo,[],guidata(gcbo))') set(handles.popupmenuY,'callback','maingui(''updateAxes'',gcbo,[],guidata(gcbo))') function setPopupmenuString(hObject,eventdata,handles)

fileName = handles.fileName;

[numbers,colNames] = xlsread(fileName);

set(hObject,'string',colNames);

function [x,y] = readExcelColumns(fileName,xColNum,yColNum)

a = xlsread(fileName);

x = a(:,xColNum); y = a(:,yColNum);

function updateAxes(hObject,eventdata,handles)

xColNum = get(handles.popupmenuX,'value')

yColNum = get(handles.popupmenuY,'value')

fileName = handles.fileName;

[x,y] = readExcelColumns(fileName,xColNum,yColNum)

plot(handles.axes1,x,y)

Answer 1

[Matt Tearle]

Run the line [numbers,colNames] = xlsread(fileName); from the Command Window (with the appropriate fileName filled in, obviously) and take a look at colNames. It is almost certainly going to be a whole cell array of text entries. This means that the actual column header strings you want are colNames{1,1} and colNames{1,2}. Because MATLAB is column-major, and allows linear indexing, I suspect that set(hObject,'string',colNames); is essentially getting colNames{1,1} and colNames{2,1} (ie going down the first column). But {2,1} is going to be blank.

So, short answer: replace

set(hObject,'string',colNames);

with

set(hObject,'string',colNames(1,1:2));

[Ean Soo]

THanks Matt, you give me a better understanding on this