/* Euclidean Distance calculation */
private double Distance(RssiValue[] unknown, AdjustedFingerprinting data)
{
double distance = 0.0;
for (int i = 0; i < unknown.Length; ++i)
{
distance += (unknown[i].Rssi - data.RssiValueAndGateway[i].Rssi) *
(unknown[i].Rssi - data.RssiValueAndGateway[i].Rssi);
}
return(Math.Sqrt(distance));
}
/* sends the command to fetch fingerprinting data from the server*/
public static List <AdjustedFingerprinting> GetFingerprintings(int environmentId)
{
/* If we fetch the fingerprintings of the environment in question.
* we do not call the server again, return them from the cache */
if (!fingerprintings.ContainsKey(environmentId))
{
/* Fetch the fingerprintings from the server and cache. */
string json = Get(string.Format($"{GET_FINGERINTING_COMMAND} -env {environmentId}"));
List <Fingerprinting> listOfFingerprinting = JsonConvert.DeserializeObject <List <Fingerprinting> >(json);
/* Create a new cache with the environment Id */
List <AdjustedFingerprinting> adjustedFingerprintings = new List <AdjustedFingerprinting>();
fingerprintings.Add(environmentId, adjustedFingerprintings);
/* There is an assumption below that is all the data will come in sorted manner.
* The data should be sorted X-axis, Y-axis, timestamp, and gateway Id.
* This sorting should be giving a list like:
* ------ x_axis -- y_axis -- timestamp -- gateway_id
* ------ 40 -- 40 -- 2018-12.. -- 1
* ------ 40 -- 40 -- 2018-12.. -- 2
* ------ 40 -- 40 -- 2018-12.. -- 3
* ------ 40 -- 40 -- 2018-12.. -- 1
* ------ 40 -- 40 -- 2018-12.. -- 2
* ------ 40 -- 40 -- 2018-12.. -- 3
*/
AdjustedFingerprinting adjustedFingerprinting = new AdjustedFingerprinting();
/* I am going to use this value to get that I completed to process all gateways
* for each of the points */
int firstGateway = listOfFingerprinting[0].GatewayId;
/* Rssi values fetched by each of the gateways will be stored on this variable.
* As soon as the gateway changes, I will be re-initializing this variable */
RssiValue rssiValue = new RssiValue();
for (int i = 0; i < listOfFingerprinting.Count; i++)
{
/* gateway changed */
if (listOfFingerprinting[i].GatewayId == firstGateway)
{
/* If the gateway is the first gateway of the list
* this means all gateways processed for the corresponding
* reference point and it is time to refresh */
adjustedFingerprinting = new AdjustedFingerprinting()
{
/* Get one of the existing points */
Coordinates = GetPoint(environmentId,
listOfFingerprinting[i].Xaxis,
listOfFingerprinting[i].Yaxis)
};
adjustedFingerprintings.Add(adjustedFingerprinting);
}
/* re-initialize the rssiValue variable */
rssiValue = new RssiValue()
{
GatewayId = listOfFingerprinting[i].GatewayId,
Rssi = (listOfFingerprinting[i].Rssi)
};
adjustedFingerprinting.RssiValueAndGateway.Add(rssiValue);
}
}
return(fingerprintings[environmentId]);
}
