Pact = input('Input value of active/real power (Pact), or press enter if N/A: ');
Pre = input('Input value of reactive power (Pre), or press enter if N/A: ');
Papp = input('Input value of apparent power (Papp), or press enter if N/A: ');
PF = input('Input value of power factor (PF), or press enter if N/A: ');
while (isempty(PF) && isempty(Pact) && isempty(Pre) && isempty(Papp)) || (isempty(Pact) && isempty(Pre)) || (isempty(Pact) && isempty(Papp)) || (isempty(Pre) && isempty(Papp))
if and(PF == isempty(PF) & Pact == isempty(Pact) & Pre == isempty(Pre) & Papp == isempty(Papp))
disp('Error, must input valid combination of Pact, Pre, Papp, & PF')
PF = input('Input value of power factor (PF), or press enter if N/A: ');
Pact = input('Input value of active/real power (Pact), or press enter if N/A: ');
Pre = input('Input value of reactive power (Pre), or press enter if N/A: ');
Papp = input('Input value of apparent power (Papp), or press enter if N/A: ');
if isempty(PF) && ~isempty(Pact) && isempty(Pre) && isempty(Papp)
disp('Error, must input valid combination of Pact, Pre, Papp, & PF')
PF = input('Input value of power factor (PF), or press enter if N/A: ');
Pre = input('Input value of reactive power (Pre), or press enter if N/A: ');
Papp = input('Input value of apparent power (Papp), or press enter if N/A: ');
if isempty(PF) && isempty(Pact) && ~isempty(Pre) && isempty(Papp)
disp('Error, must input valid combination of Pact, Pre, Papp, & PF')
PF = input('Input value of power factor (PF), or press enter if N/A: ');
Pact = input('Input value of active/real power (Pact), or press enter if N/A: ');
Papp = input('Input value of apparent power (Papp), or press enter if N/A: ');
if isempty(PF) && isempty(Pact) && isempty(Pre) && ~isempty(Papp)
disp('Error, must input valid combination of Pact, Pre, Papp, & PF')
PF = input('Input value of power factor (PF), or press enter if N/A: ');
Pact = input('Input value of active/real power (Pact), or press enter if N/A: ');
Pre = input('Input value of reactive power (Pre), or press enter if N/A: ');