repeated measure anova two options

Hello,

I am trying to use repeated measure ANOVA “ranova” in MATLAB. According to MATLAB tutorial, there are two option: 1: ranova(rm) and 2: ranova(rm,'WithinModel',WM).

I tried both and they give different results for the within model analysis (in my example the within model variable is time; I have repeated measurements). Option 1 has a closer results to those produced by other software like R; however, it does not give me the between model results which are the main effect of between model variables and their interactions. I appreciate it if you let me know what the difference is.

Also, the sums of squares are not the same as what I get from R. Could you please help me find out about this discrepancy?

Best,

Sepideh.

[Sophi Af]

I have included my code here. The data is measurement of mice brain at 8 regions; thus, I am running 8 ranova.

tr=cell(length(tr_p),1);

gr=cell(length(tr_p),1);

for i=1:length(tr_p)

tr{i}=int2str(tr_p(i));

gr{i}=int2str(gr_p(i));

end

for i=1:8

Y1=DaB_a1(:,i);

Y2=DaB_a2(:,i);

Y=[Y1,Y2];

tr_cat=categorical(tr);

gr_cat=categorical(gr);

varnames = {'treatment','disorder','A1','A2'};

t=table(tr_cat,gr_cat,Y1,Y2,'VariableNames',varnames);

% Time=[1 2];

T = table([1 2]','VariableNames',{'Time'});

rm=fitrm(t,'A1-A2 ~ treatment*disorder','WithinDesign', T);

% rm=fitrm(t,'A1-A2 ~ treatment*disorder','WithinModel', Time, 'WithinModel', 'separatemeans');

% [ran0] = ranova(rm);

[ran1] = ranova(rm,'WithinModel','Time');

[ran0] = ranova(rm);

adj1=epsilon(rm);

M1=multcompare(rm, 'Time', 'By', 'treatment');

M2=multcompare(rm, 'Time', 'By', 'disorder');

tr_cat=categorical(tr);

gr_cat=categorical(gr);

intr_cat=tr_cat.*gr_cat;

varnames_cat = {'intr_cat','A1','A2'};

t=table(intr_cat,Y1,Y2,'VariableNames',varnames_cat);

rm=fitrm(t,'A1-A2 ~ intr_cat','WithinModel', Time, 'WithinModel', 'separatemeans');

% [ran2] = ranova(rm);

[ran3] = ranova(rm,'WithinModel','Time');

adj3=epsilon(rm);

M3=multcompare(rm, 'Time', 'By', 'intr_cat');

1;

end

Answer 1

[Jeff Miller]

Not sure but I think you need

T = table([1 2]','VariableNames',{'Time'});
T.Time = categorical(T.Time);  % add this line

Maybe post one of your 't' data tables so the design is clearer?

[Sophi Af]

Hello,

Thank you for your reply. I guess my main issue is the difference between the results of two option: 1: ranova(rm) and 2: ranova(rm,'WithinModel',WM).

I have attached one of my t table data to this email. The data has been recorded in 8 brain areas but I am looking into only the first area now (first data sheet).

I appreciate your help.

Best,

Sepideh.

[Jeff Miller]

If each line of your t table represents a different person, then you should use the ranova command including 'WithinModel'.

[Sophi Af]

Unfortunately, when I use the command including 'WithinModel' the results doesnt make sense including the degrees of freedom. Furthermore, the results are going to be far from what I get from other softwares like R.