Time-series flood damage simulation in GAMA: .asc matrix loading issue

[Mengxue Zhang]

Hello, everyone. I am working on a flood simulation where I need to dynamically load damage value data over time to visualize the flood progression. The damage values are in float64 format, so I converted the data into .asc format (ESRI ASCII raster).

My goal is to load different .asc files at each time step using a matrix<float> to assign values dynamically to a predefined grid. However, I encountered a "matrix index out of bounds" error during runtime.

Based on my testing  I suspect the issue is due to the .asc files including a 6-line header (containing ncols, nrows, etc.), which is not automatically skipped when using matrix(file(...)). 

What is the correct way to dynamically load .asc files?  Or is there a better practice within GAMA to parse the data correctly?

Thank you for all your help.

the script is as follow:

model asc

/* Insert your model definition here */

global {

list<string> file_paths <- [

"E:/dv_distributed_1step.asc",

"E:/dv_distributed_2step.asc"

];

int my_step <- 0;

matrix<float> current_data;

float nodata <- -9999;

int val_color;

file grid_data1 <- file('E:/dv_distributed_1step1.asc');

geometry shape <- envelope(grid_data1);

//init

init {

current_data <- matrix(file(file_paths[my_step]));

ask flood_cell { do load_step; }

}

// reflex

reflex update_step when: my_step < length(file_paths) - 1 {

my_step <- my_step + 1;

current_data <- matrix(file(file_paths[my_step]));

ask flood_cell { do load_step; }

}

}

grid flood_cell width: 176 height: 371 {

float water <- 0.0;

action load_step {

if (grid_y < length(current_data) and grid_x < length(current_data[0])) {

float grid_value <- current_data[grid_y, grid_x];

val_color <- max([0, min([255, int(255 * (1 - (grid_value / 10)) )])]);

color <- [val_color, val_color, 255];

} else {

write "beyond: grid_x=" + grid_x + " grid_y=" + grid_y;

}

}

}

experiment flood_demo type: gui {

output {

display "Flood" type:2d{

grid flood_cell ;

}

}

}

[Benoit Gaudou]

Dear,

Sorry for the late reply.

Basically out of bounds error occurs when you accept to index(es) out of the dimension of a matrix.

In that case, it occurs here when grid_y is greater than the highest value of grid_x : 

float grid_value <- current_data[grid_y, grid_x];

so you can just inverse the order of grid_x and grid_y to get the good behavior:

float grid_value <- current_data[grid_x,grid_y];

Cheers

Benoit

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