I want to make a contour/surface plot, which shows the values in the cells, similar to an EFI tuning map

Question

I want to make something like this in MATLAB. This is a map which has x and y axis and a value for the z axis with a color for the magnitude of the z value. Basically a countour map which prints values in the matrix on the screen

Sample graph:

Answer 1

Modifying an imagesc() Plot

Here is something that might be similar enough by modifying an imagesc plot with text annotations and the line() function to create the grid. Some axis attributes including axis replacement needed to be done to configure the plot correctly. Unfortunately, it's not a very concise way of doing it but it might satisfy your application.

Engine_Load = [0.35 0.55 0.7 0.87 1 1.15 1.25 1.35 1.45 1.6 1.7 1.8 2 2.2 2.5];
Engine_Speed = (800:400:7600);

%Creating random test data%
[Engine_Load_Grid,Engine_Speed_Grid] = meshgrid(Engine_Load,Engine_Speed);
Estimated_Air_Fuel_Ratio = rand(length(Engine_Speed),length(Engine_Load));

%Creating the grid structure%
X_Axis = (1:length(Engine_Load));
Y_Axis = (1:length(Engine_Speed));
[X_Grid,Y_Grid] = meshgrid(X_Axis,Y_Axis);

clf;
imagesc('XData',X_Axis,'YData',Y_Axis,'CData',Estimated_Air_Fuel_Ratio);
xticks(1:1:length(X_Axis));
yticks(1:1:length(Y_Axis));
xlim([0.5 length(X_Axis)+0.5]);
ylim([0.5 length(Y_Axis)+0.5]);
Current_Axis = gca;
Current_Axis.XAxisLocation = 'Top';
grid on;

for Horizontal_Lines = 1: length(yticks)
line([0.5 length(X_Axis)+0.5],[Horizontal_Lines+0.5 Horizontal_Lines+0.5],'color','w','LineWidth',2);
end

for Vertical_Lines = 1: length(yticks)
line([Vertical_Lines+0.5 Vertical_Lines+0.5],[0.5 length(Y_Axis)+0.5],'color','w','LineWidth',2);
end

Estimated_Air_Fuel_Ratio = flip(Estimated_Air_Fuel_Ratio);
[Matrix_Height,Matrix_Width] = size(Estimated_Air_Fuel_Ratio);
for Row_Index = 1: Matrix_Height
    for Column_Index = 1: Matrix_Width
        
    text(Column_Index,Matrix_Height+1-Row_Index,num2str(Estimated_Air_Fuel_Ratio(Row_Index,Column_Index)));
    
    end
end

Current_Figure = gcf;
set(findall(gcf,'type','text'),'HorizontalAlignment','center')
set(Current_Axis,'xtick',X_Axis,'xticklabel',Engine_Load);
set(Current_Axis,'ytick',Y_Axis,'yticklabel',Engine_Speed);
xlabel('Engine Load'); ylabel('Engine Speed');
colorbar

Current_Figure.Position = [0 0 1000 1000];

Ran using MATLAB R2019b