Please help this semilogy error message

can you tell me what is wrong with this line ؟

it says

Error using semilogy

Not enough input arguments.

semilogy (BestCost(1,:),

'LineWidth',2,'Color','r',BestCost(2,:),'LineWidth',2,'Color','b')

figure;
semilogy (BestCost(1,:), 'LineWidth',2,'Color','r',BestCost(2,:),'LineWidth',2,'Color','b')
xlabel('Iteration');
ylabel('Best Cost');
legend('normal','stop and watch')
grid on;
hold on

thank you

[dpb]

Implicit x values are accepted for only one y argument; the multiple triplets form works for only x,y pairs.

hL=semilogy (BestCost(1:2,:).', 'LineWidth',2)

should work to do the same thing using the builtin feature to plot arrays by column.

[ahmed mer]

it only shows one graph

[Star Strider]

It shows one line because it assumes that ‘BestCost(1,:)’ are the ‘x’ ccordinates and ‘BestCost(2,:)’ are the ‘y’ coordinates.

To plot both as individual plots, try something like this —

BestCost = [rand(1,10); rand(1,10)];

figure;
semilogy(BestCost(1,:), 'LineWidth',2,'Color','r')
hold on
plot(BestCost(2,:),'LineWidth',2,'Color','b')
hold off
xlabel('Iteration');
ylabel('Best Cost');
legend('normal','stop and watch')
grid on;
hold on

The second plot inherits the axes of the first plot, so they will both appear on semilogy axes.

.

[dpb]

BestCost = [rand(1,10); rand(1,10)];

semilogy(BestCost.','linewidth',2)
xlabel('Iteration');
ylabel('Best Cost');
legend('normal','stop and watch')
grid on;

Don't need explicit x nor to plot each individually -- the one argument as a 2-column array uses the builtin interpretation by plot and friends to treat columns as separate variables; it rotates through the default colormap automagically, too.

[Walter Roberson]

semilogy (BestCost(1,:), 'LineWidth',2,'Color','r',BestCost(2,:),'LineWidth',2,'Color','b')

In the plotting functions, once you have start the first name/value pair, everything else on the line must be name/value pairs.

The plotting functions do not permit adding name/value pairs for each distinct set of data: the name/value pairs must go after all data specifications, and the name/value pairs will apply to all sets of data in the same call.